[FFmpeg-devel,WIP] libcodec2 wrapper + de/muxer in FFmpeg

Submitted by Tomas Härdin on Aug. 3, 2017, 3:45 p.m.

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Message ID 1501775122.19937.96.camel@acc.umu.se
State Superseded
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Commit Message

Tomas Härdin Aug. 3, 2017, 3:45 p.m.
On Thu, 2017-08-03 at 13:00 +0200, Nicolas George wrote:
> Le sextidi 16 thermidor, an CCXXV, Tomas Härdin a écrit :
> > With both the raw demuxer and the encoder you need to specify the
> > desired mode, like this:
> The encoder could default to one the two.

Default on-the-air is 1300 (aka FreeDV 1600), so that seems like a
reasonable default

> > Some remarks:
> > 
> > * I had to make the ffmpeg CLI not complain about the 700 modes,
> > since
> > it thinks encoding at below 1 kbps is a user error
> It is just a warning. I am not really a fan of a special case like
> that,
> and it would be better split into a separate patch I think.

There's other codec-specific special cases in ffmpeg.c, like the one
for AV_CODEC_ID_VP9 which doesn't even have an explanation. Separate
patch is a good idea however.

> > * I have duplicated some minor functions in libcodec2 in
> > libavcodec/codec2utils.*. This avoid having to link libcodec2 just
> > for
> > remuxing, and in case someone writes a native decoder for
> > libavcodec
> The license allows it, but you neglected to give copyright
> attribution.

Alright, I can fix that. Although the only thing lifted straight are
the mode #defines

> > * Not sure if codec2utils should go in libavutil, libavcodec felt
> > good
> > enough
> Definitely libavcodec.

Cool.

> > 
> > * The demuxer tries to read up to 0.1 seconds worth of frames to
> > speed
> > things up a little without making seeking too broken. 3 frames = 12
> > bytes for the 700 bit/s modes, which decode to 960 samples
> I do not like the sound of that, but I will see the code.
> 
> > 
> > * The decoder is able to deal with multiple frames at a time, the
> > encoder does not need to
> ???

The encoder is given frame_size number of samples each time. Are there
times where this is not the case? I haven't set
AV_CODEC_CAP_SMALL_LAST_FRAME.

> > Feel free to bikeshed around whether extradata should be the entire
> > .c2
> > header or just the mode byte. It really only matters if we go with
> > RIFF
> > or ISOM mappings (.wav .avi .mov and friends), which I decided to
> > leave
> > out for now.
> It matters for inclusion in any format: Matroska, Nut, etc. Is
> anybody
> considering normalization?

I raised the possibility on [Freetel-codec2], either by coding mode as
part of the TwoCC (0xC208 for mode 8 for examples) or via extradata. I
imagine version + mode + flags in extradata would not be unreasonable.

> > +libcodec2_decoder_deps="libcodec2"
> > +libcodec2_decoder_select="codec2utils"
> > +libcodec2_encoder_deps="libcodec2"
> > +libcodec2_encoder_select="codec2utils"
> This and the similar hunks are not necessary, see below the comments
> about the Makefile.

I presume you mean codec2utils and not the libcodec2 deps.

> > +OBJS-$(CONFIG_CODEC2UTILS)             += codec2utils.o
> You do not need a separate configuration option, you can just depend
> on
> the actual visible option:
> 
> +OBJS-$(CONFIG_CODEC2_DEMUXER)           += codec2utils.o
> +OBJS-$(CONFIG_CODEC2_MUXER)             += codec2utils.o
> 
> Having the same file several times will not cause it to be included
> several times.
> 
> > +OBJS-$(CONFIG_LIBCODEC2_DECODER)          += libcodec2.o
> > +OBJS-$(CONFIG_LIBCODEC2_ENCODER)          += libcodec2.o
> +OBJS-$(CONFIG_LIBCODEC2_DECODER)          += libcodec2.o
> codec2utils.o
> +OBJS-$(CONFIG_LIBCODEC2_ENCODER)          += libcodec2.o
> codec2utils.o

Fixed.

> > +++ b/libavcodec/codec2utils.c
> > @@ -0,0 +1,118 @@
> > +/*
> > + * codec2 utility functions
> > 
> > + * Copyright (c) 2017 Tomas Härdin
> Missing copyright attribution if the imported code is non-trivial
> (better err on the side of more attribution).

Guess I'll nick the comment from the relevant files in libcodec2.


> > 
> > +int avpriv_codec2_mode_from_str(void *logctx, const char *modestr)
> > {
> Please normalize the coding style. Same below.

I presume you mean putting the function opening braces on their own
lines like the rest of FFmpeg. Fixed.

> > 
> > +    //statically assert the size of avpriv_codec2_header
> > +    //putting it here because all codec2 things depend on
> > codec2utils
> > +    switch(0) {
> > +    case 0:
> > +    case sizeof(avpriv_codec2_header) == 7: //if false then the
> > compiler will complain
> > +        break;
> > +    }
> I see how it works. This is a nice trick. Want to make it an official
> macro FF_ASSERT_STATIC()?

Sure. Could go in avutil.h or something. Maybe even inside a static
function with a fake name like:

#define FF_ASSERT_STATIC(x, name) static void name(){switch(0){...}}

Didn't do that in this patchset however.

> > +int avpriv_codec2_mode_bit_rate(void *logctx, int mode) {
> > 
> > +    int ret = 8 * 8000 * avpriv_codec2_mode_block_align(logctx,
> > mode) / avpriv_codec2_mode_frame_size(logctx, mode);
> > +    if (ret <= 0) {
> > +        av_log(logctx, AV_LOG_WARNING, "unknown codec2 mode %i,
> > can't estimate bitrate\n", mode);
> I bet you did not test the invalid case. Otherwise, I think you would
> have found a division by 0.

Yep, I found it as soon as I crafted a file with an unknown mode.
Running afl-fuzz right now to see if there's some other fun problems.

> > +int avpriv_codec2_mode_frame_size(void *logctx, int mode) {
> > +    switch (mode) {
> > 
> > +    case CODEC2_MODE_3200: return 160;
> > +    case CODEC2_MODE_2400: return 160;
> > +    case CODEC2_MODE_1600: return 320;
> > +    case CODEC2_MODE_1400: return 320;
> > +    case CODEC2_MODE_1300: return 320;
> > +    case CODEC2_MODE_1200: return 320;
> > +    case CODEC2_MODE_700:  return 320;
> > +    case CODEC2_MODE_700B: return 320;
> > +    case CODEC2_MODE_700C: return 320;
> For all these mappings, I think a table would be more elegant.

Sure. it could take its size from the largest known mode ID + 1.

> > +avpriv_codec2_header avpriv_codec2_make_header(int mode) {
> > +    avpriv_codec2_header header = {
> > +        .magic = {0xC0, 0xDE, 0xC2},
> > +        //version 0.8 as of 2017-08-02 (r3345)
> > +        .version_major = 0,
> > +        .version_minor = 8,
> > +        .mode = mode,
> > +        .flags = 0,
> > +    };
> > +    return header;
> > +}
> This would be more efficient as static inline.

Fixed.

> > +#ifndef AVCODEC_CODEC2UTILS_H
> > +#define AVCODEC_CODEC2UTILS_H
> > +
> > 
> > +#include "internal.h"
> Why?

For uint8_t. But perhaps FFmpeg relies on <stdint.h> existing? MSVC is
a pain etc.
Changed to #include <stdint.h>

> > 
> > +typedef struct {
> Anonymous structures are discouraged.
> 
> > 
> > +    uint8_t magic[3];
> > +    uint8_t version_major;
> > +    uint8_t version_minor;
> > +    uint8_t mode;
> > +    uint8_t flags;
> > 
> > +} avpriv_codec2_header;
> Types and structures names do not need to be namespaced when they are
> private. On the other hand, the case is not consistent with the rest
> of
> the code.

So what should I go with? Something like

typedef struct ff_codec2_header {
} ff_codec2_header;

? Using codec2_ as a prefix is likely a Bad Idea since libcodec2 does
that :)
I saw avpriv_ used in various places so I went with that.
Fixed the anonymousness at least.

> > +++ b/libavcodec/codec_desc.c
> > @@ -2657,6 +2657,13 @@ static const AVCodecDescriptor
> > codec_descriptors[] = {
> >          .props     = AV_CODEC_PROP_LOSSY,
> >      },
> >      {
> > +        .id        = AV_CODEC_ID_CODEC2,
> > +        .type      = AVMEDIA_TYPE_AUDIO,
> > +        .name      = "codec2",
> > 
> > +        .long_name = NULL_IF_CONFIG_SMALL("codec2"),
> Not helpful.

Suggestions? I could link freedv.org, or maybe a short blurb like
"codec2 (very low bitrate speech codec, see freedv.org)"

> > +typedef struct {
> > +    const AVClass *class;
> > +    struct CODEC2 *codec;
> > +    char *mode;
> > 
> > +} libcodec2_context;
> Case not consistent with the rest of the code.

My code or FFmpeg code? I see avidec.c uses AVIContext, so I assume the
latter. Changed to Codec2Context and LibCodec2Context in relevant
files.

> > 
> > +
> > +static const AVOption options[] = {
> > 
> > +    //not AV_OPT_FLAG_DECODING_PARAM since mode should come from
> > the demuxer
> ??? If it comes from the raw demuxer, it is still a decoding param,
> is
> it not?

Yes but it is carried in extradata. You shouldn't have to set it on the
decoder. Plus it would create a contradiction - "does -mode apply to
the decoder or the demuxer?"

> > 
> > +    { "mode", "codec2 mode", offsetof(libcodec2_context, mode),
> > AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_AUDIO_PARAM |
> > AV_OPT_FLAG_ENCODING_PARAM },
> I think it would be better to make the mode option an integer and use
> the CONST system to expose the valid values. Same below.

Cool, I didn't know that. That would remove the need
for avpriv_codec2_mode_from_str().

> > +static const AVClass codec2_class = {
> > +    .class_name = "libcodec2",
> > +    .item_name  = av_default_item_name,
> > +    .option     = options,
> > +    .version    = LIBAVUTIL_VERSION_INT,
> > +};
> IIRC, you cannot use the same class for two components. Does "ffmpeg
> -h
> full" still work?

Well, I get -mode listed in the two expected places:

  libcodec2 AVOptions:
    -mode              <string>     E...A... codec2 mode

  codec2 AVOptions:
    -mode              <string>     .D...... codec2 mode

To be more helpful I suppose they could be given different names like
"libcodec2 decoder", "libcodec2 encoder", "codec2raw demuxer", "codec2
(.c2) demuxer" and so on

> > +    } else {
> > +        if (avctx->extradata_size != sizeof(avpriv_codec2_header))
> > {
> > +            av_log(avctx, AV_LOG_ERROR, "must have exactly %zu
> > bytes of extradata (got %i)\n",
> > +                   sizeof(avpriv_codec2_header), avctx-
> > >extradata_size);
> return AVERROR_INVALIDDATA?

Good catch, fixed. Should AVERROR_INVALIDDATA be preferred over
AVERROR(EINVAL) perhaps? I've seen both used almost interchangably.

> > +    output = (int16_t *)frame->data[0];
> > +
> > +    for (i = 0; i < nframes; i++) {
> > 
> > +        codec2_decode(c2->codec, &output[i*avctx->frame_size],
> > &pkt->data[i*avctx->block_align]);
> I suggest:
> 
>     input  += avctx->frame_size;
>     output += avctx->frame_size;
> 
> and drop the multiplication.

Reasonable enough

> > +
> > +AVCodec ff_libcodec2_decoder = {
> > +    .name                   = "libcodec2",
> > 
> > +    .long_name              = NULL_IF_CONFIG_SMALL("codec2
> > encoder/decoder using libcodec2"),
> This is not an encoder.
> > +    .long_name              = NULL_IF_CONFIG_SMALL("codec2
> > encoder/decoder using libcodec2"),
> And this is not a decoder.

Fixed.

> > +static int codec2_probe(AVProbeData *p)
> > +{
> > +    if (p->buf_size < sizeof(avpriv_codec2_header)) {
> > +        return 0;
> > +    }
> > +
> > +    //file starts wih 0xC0DEC2
> > 
> > +    if (p->buf[0] == 0xC0 && p->buf[1] == 0xDE && p->buf[2] ==
> > 0xC2) {
> > +        return AVPROBE_SCORE_MAX;
> As pointed by Carl Eugen, this is not reliable enough. The problem is
> not misdetecting the version of files, the problem is detecting files
> that are not codec2 as codec2. A lot of files can start with 192 222
> 194.

Noted. I made the probe function a bit fancier, files where only these
three bytes match get a score of 10. Files with modes and minor
versions we don't know about get slightly penalized. There should also
be no .c2 files with version < 0.8 (as verified by Nivex on #freedv)

> > 
> > +    //replicating estimate_timings_from_bit_rate() in utils.c to
> > avoid warnings
> Please elaborate.

Without this utils.c nags about duration not being known. It would be
nice if there was a flag to shut it up for CBR formats

> > +    if (st->codecpar->extradata[0] != 0xC0 ||
> > +        st->codecpar->extradata[1] != 0xDE ||
> > +        st->codecpar->extradata[2] != 0xC2) {
> Since you do it twice, you could make it a function.

Done.

> > 
> > +        av_log(s, AV_LOG_ERROR, "not a .c2 file\n");
> > +    }
> I think setting the time base information is missing.

That is done in codec2_read_header_common()

> > 
> > +    //Read roughly 0.1 seconds worth of data.
> > +    n = st->codecpar->bit_rate / ((int)(8/0.1) * block_align) + 1;
> I do not like that block. Maybe make it an option?

I'd rather just read block_size bytes in that case, an option seems
excessive. Or maybe someone wants to transcode huge amounts of speech
as fast as possible. Hm...

-blocks_per_packet maybe? With a help string like "read multiple blocks
at a time, useful for processing large amounts of data"

> > +
> > +//based off of ff_raw_read_partial_packet()
> > +static int codec2_read_packet(AVFormatContext *s, AVPacket *pkt)
> > +{
> > +    AVStream *st = s->streams[0];
> > +    int ret, size, n, block_align, frame_size;
> > +
> > +    block_align = st->codecpar->block_align;
> > +    frame_size  = st->codecpar->frame_size;
> > > > ++        return ret;
> > +    }
> > +    av_shrink_packet(pkt, ret);
> av_get_packet()?

The SANE_CHUNK_SIZE logic in it looks a bit scary. There's a bug in
this patch however, it should use avio_read() not ffio_read_partial().
I want to be damn sure only multiples of block_align are read. Maybe
someone out there has files with 139 hours of speech in them, who
knows?

> > 
> > +        av_log(s, AV_LOG_ERROR, ".c2 files require exactly %zu
> > bytes of extradata (got %i)\n",
> IIRC, the z modifier is broken on some proprietary system. I
> personally
> do not care.

Portable size_t format strings are a pain, added a cast to int instead.

Thanks for the review. New patchset attached. Some things still TODO,
like tableizing codec2utils and the numerical -mode option thing.
Didn't compile yet because afl-fuzz is still running, and I'm going to
let it run while I'm out and about.

/Tomas

Comments

Hendrik Leppkes Aug. 3, 2017, 3:59 p.m.
On Thu, Aug 3, 2017 at 5:45 PM, Tomas Härdin <tjoppen@acc.umu.se> wrote:
>> > +    } else {
>> > +        if (avctx->extradata_size != sizeof(avpriv_codec2_header))
>> > {
>> > +            av_log(avctx, AV_LOG_ERROR, "must have exactly %zu
>> > bytes of extradata (got %i)\n",
>> > +                   sizeof(avpriv_codec2_header), avctx-
>> > >extradata_size);
>> return AVERROR_INVALIDDATA?
>
> Good catch, fixed. Should AVERROR_INVALIDDATA be preferred over
> AVERROR(EINVAL) perhaps? I've seen both used almost interchangably.
>

Generally, AVERROR_INVALIDDATA is for invalid bitstreams (which
extradata would be a part of), AVERROR(EINVAL) for invalid
user-provided options/settings.
Not all code follows that quite strictly, but thats the usual
definition we use around here.

- Hendrik

Patch hide | download patch | download mbox

From f0247619c23e5753549b51143aa9c891b4705129 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomas=20H=C3=A4rdin?= <tjoppen@acc.umu.se>
Date: Wed, 2 Aug 2017 22:17:19 +0200
Subject: [PATCH 1/2] Add codec2 muxers, demuxers and en/decoder via libcodec2

---
 Changelog                |   2 +
 configure                |   5 +
 doc/general.texi         |  13 +++
 libavcodec/Makefile      |   2 +
 libavcodec/allcodecs.c   |   1 +
 libavcodec/avcodec.h     |   1 +
 libavcodec/codec2utils.c | 103 +++++++++++++++++
 libavcodec/codec2utils.h |  86 ++++++++++++++
 libavcodec/codec_desc.c  |   7 ++
 libavcodec/libcodec2.c   | 196 ++++++++++++++++++++++++++++++++
 libavcodec/version.h     |   2 +-
 libavformat/Makefile     |   4 +
 libavformat/allformats.c |   2 +
 libavformat/codec2.c     | 289 +++++++++++++++++++++++++++++++++++++++++++++++
 libavformat/rawenc.c     |  13 +++
 libavformat/utils.c      |   1 +
 libavformat/version.h    |   2 +-
 17 files changed, 727 insertions(+), 2 deletions(-)
 create mode 100644 libavcodec/codec2utils.c
 create mode 100644 libavcodec/codec2utils.h
 create mode 100644 libavcodec/libcodec2.c
 create mode 100644 libavformat/codec2.c

diff --git a/Changelog b/Changelog
index 187ae7950a..e28da7dcc4 100644
--- a/Changelog
+++ b/Changelog
@@ -29,6 +29,8 @@  version <next>:
 - limiter video filter
 - libvmaf video filter
 - Dolby E decoder and SMPTE 337M demuxer
+- codec2 en/decoding via libcodec2
+- muxer/demuxer for raw codec2 files and .c2 files
 
 version 3.3:
 - CrystalHD decoder moved to new decode API
diff --git a/configure b/configure
index 66c7b948e4..50f455af71 100755
--- a/configure
+++ b/configure
@@ -220,6 +220,7 @@  External library support:
   --enable-libcaca         enable textual display using libcaca [no]
   --enable-libcelt         enable CELT decoding via libcelt [no]
   --enable-libcdio         enable audio CD grabbing with libcdio [no]
+  --enable-libcodec2       enable codec2 en/decoding using libcodec2 [no]
   --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                            and libraw1394 [no]
   --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
@@ -1540,6 +1541,7 @@  EXTERNAL_LIBRARY_LIST="
     libbs2b
     libcaca
     libcelt
+    libcodec2
     libdc1394
     libflite
     libfontconfig
@@ -2863,6 +2865,8 @@  pcm_mulaw_at_encoder_select="audio_frame_queue"
 chromaprint_muxer_deps="chromaprint"
 h264_videotoolbox_encoder_deps="videotoolbox_encoder pthreads"
 libcelt_decoder_deps="libcelt"
+libcodec2_decoder_deps="libcodec2"
+libcodec2_encoder_deps="libcodec2"
 libfdk_aac_decoder_deps="libfdk_aac"
 libfdk_aac_encoder_deps="libfdk_aac"
 libfdk_aac_encoder_select="audio_frame_queue"
@@ -5837,6 +5841,7 @@  enabled libcelt           && require libcelt celt/celt.h celt_decode -lcelt0 &&
                              { check_lib libcelt celt/celt.h celt_decoder_create_custom -lcelt0 ||
                                die "ERROR: libcelt must be installed and version must be >= 0.11.0."; }
 enabled libcaca           && require_pkg_config caca caca.h caca_create_canvas
+enabled libcodec2         && require libcodec2 codec2/codec2.h codec2_create -lcodec2
 enabled libdc1394         && require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new
 enabled libfdk_aac        && { use_pkg_config fdk-aac "fdk-aac/aacenc_lib.h" aacEncOpen ||
                                { require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac &&
diff --git a/doc/general.texi b/doc/general.texi
index 036c8c25d4..4bcc2b2d91 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -85,6 +85,15 @@  Go to @url{http://www.twolame.org/} and follow the
 instructions for installing the library.
 Then pass @code{--enable-libtwolame} to configure to enable it.
 
+@section libcodec2
+
+FFmpeg can make use of libcodec2 to codec2 encoding and decoding.
+There is currently no native decoder, so libcodec2 must be used for decoding.
+
+Go to @url{http://freedv.org/}, download "Codec 2 source archive".
+Build and install using CMake. Debian users can install the libcodec2-dev package instead.
+Once libcodec2 is installed you can pass @code{--enable-libcodec2} to configure to enable it.
+
 @section libvpx
 
 FFmpeg can make use of the libvpx library for VP8/VP9 encoding.
@@ -290,6 +299,8 @@  library:
 @item BRSTM                     @tab   @tab X
     @tab Audio format used on the Nintendo Wii.
 @item BWF                       @tab X @tab X
+@item codec2 (raw)              @tab X @tab X
+@item codec2 (.c2 files)        @tab X @tab X
 @item CRI ADX                   @tab X @tab X
     @tab Audio-only format used in console video games.
 @item Discworld II BMV          @tab   @tab X
@@ -994,6 +1005,8 @@  following image formats are supported:
     @tab Used in Bink and Smacker files in many games.
 @item CELT                   @tab     @tab  E
     @tab decoding supported through external library libcelt
+@item codec2                 @tab  E  @tab  E
+    @tab en/decoding supported through external library libcodec2
 @item Delphine Software International CIN audio  @tab     @tab  X
     @tab Codec used in Delphine Software International games.
 @item Digital Speech Standard - Standard Play mode (DSS SP) @tab     @tab  X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 74de41ab0f..dab3d00f30 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -885,6 +885,8 @@  OBJS-$(CONFIG_ILBC_AT_ENCODER)            += audiotoolboxenc.o
 OBJS-$(CONFIG_PCM_ALAW_AT_ENCODER)        += audiotoolboxenc.o
 OBJS-$(CONFIG_PCM_MULAW_AT_ENCODER)       += audiotoolboxenc.o
 OBJS-$(CONFIG_LIBCELT_DECODER)            += libcelt_dec.o
+OBJS-$(CONFIG_LIBCODEC2_DECODER)          += libcodec2.o codec2utils.o
+OBJS-$(CONFIG_LIBCODEC2_ENCODER)          += libcodec2.o codec2utils.o
 OBJS-$(CONFIG_LIBFDK_AAC_DECODER)         += libfdk-aacdec.o
 OBJS-$(CONFIG_LIBFDK_AAC_ENCODER)         += libfdk-aacenc.o
 OBJS-$(CONFIG_LIBGSM_DECODER)             += libgsmdec.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 4712592a5f..5296fac507 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -618,6 +618,7 @@  static void register_all(void)
     REGISTER_DECODER(QDMC_AT,           qdmc_at);
     REGISTER_DECODER(QDM2_AT,           qdm2_at);
     REGISTER_DECODER(LIBCELT,           libcelt);
+    REGISTER_ENCDEC (LIBCODEC2,         libcodec2);
     REGISTER_ENCDEC (LIBFDK_AAC,        libfdk_aac);
     REGISTER_ENCDEC (LIBGSM,            libgsm);
     REGISTER_ENCDEC (LIBGSM_MS,         libgsm_ms);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index c594993766..488eb8b1f5 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -622,6 +622,7 @@  enum AVCodecID {
     AV_CODEC_ID_PAF_AUDIO,
     AV_CODEC_ID_ON2AVC,
     AV_CODEC_ID_DSS_SP,
+    AV_CODEC_ID_CODEC2,
 
     AV_CODEC_ID_FFWAVESYNTH = 0x15800,
     AV_CODEC_ID_SONIC,
diff --git a/libavcodec/codec2utils.c b/libavcodec/codec2utils.c
new file mode 100644
index 0000000000..8812f1a98f
--- /dev/null
+++ b/libavcodec/codec2utils.c
@@ -0,0 +1,103 @@ 
+/*
+ * codec2 utility functions
+ * Copyright (c) 2017 Tomas Härdin
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+#include "internal.h"
+#include "libavcodec/codec2utils.h"
+
+int avpriv_codec2_mode_from_str(void *logctx, const char *modestr)
+{
+    //statically assert the size of avpriv_codec2_header
+    //putting it here because all codec2 things depend on codec2utils
+    switch(0) {
+    case 0:
+    case sizeof(avpriv_codec2_header) == 7: //if false then the compiler will complain
+        break;
+    }
+
+    if (!modestr) {
+        av_log(logctx, AV_LOG_ERROR, "raw codec2 streams need -mode set\n");
+        return AVERROR(EINVAL);
+    }
+
+#define MATCH(x) do { if (!strcmp(modestr, #x)) { return CODEC2_MODE_##x; } } while (0)
+    MATCH(3200);
+    MATCH(2400);
+    MATCH(1600);
+    MATCH(1400);
+    MATCH(1300);
+    MATCH(1200);
+    MATCH(700);
+    MATCH(700B);
+    MATCH(700C);
+
+    av_log(logctx, AV_LOG_ERROR, "invalid codec2 mode: %s\n", modestr);
+    return AVERROR(EINVAL);
+}
+
+int avpriv_codec2_mode_bit_rate(void *logctx, int mode)
+{
+    int frame_size, block_align;
+
+    if ((frame_size  = avpriv_codec2_mode_frame_size(logctx, mode)) <= 0 ||
+        (block_align = avpriv_codec2_mode_block_align(logctx, mode)) <= 0) {
+        return 0;
+    }
+
+    return 8 * 8000 * block_align / frame_size;
+}
+
+//TODO: make tables, per nicolas' suggestion
+int avpriv_codec2_mode_frame_size(void *logctx, int mode)
+{
+    switch (mode) {
+    case CODEC2_MODE_3200: return 160;
+    case CODEC2_MODE_2400: return 160;
+    case CODEC2_MODE_1600: return 320;
+    case CODEC2_MODE_1400: return 320;
+    case CODEC2_MODE_1300: return 320;
+    case CODEC2_MODE_1200: return 320;
+    case CODEC2_MODE_700:  return 320;
+    case CODEC2_MODE_700B: return 320;
+    case CODEC2_MODE_700C: return 320;
+    default:
+        av_log(logctx, AV_LOG_ERROR, "unknown codec2 mode %i, can't find frame_size\n", mode);
+        return 0;
+    }
+}
+
+int avpriv_codec2_mode_block_align(void *logctx, int mode)
+{
+    switch (mode) {
+    case CODEC2_MODE_3200: return 8;
+    case CODEC2_MODE_2400: return 6;
+    case CODEC2_MODE_1600: return 8;
+    case CODEC2_MODE_1400: return 7;
+    case CODEC2_MODE_1300: return 7;
+    case CODEC2_MODE_1200: return 6;
+    case CODEC2_MODE_700:  return 4;
+    case CODEC2_MODE_700B: return 4;
+    case CODEC2_MODE_700C: return 4;
+    default:
+        av_log(logctx, AV_LOG_ERROR, "unknown codec2 mode %i, can't find block_align\n", mode);
+        return 0;
+    }
+}
diff --git a/libavcodec/codec2utils.h b/libavcodec/codec2utils.h
new file mode 100644
index 0000000000..c28a253ac6
--- /dev/null
+++ b/libavcodec/codec2utils.h
@@ -0,0 +1,86 @@ 
+/*
+ * codec2 utility functions
+ * Copyright (c) 2017 Tomas Härdin
+ *
+ * Constants taken from codec2.h in libcodec2, which is also under the LGPL 2.1
+ * Copyright (C) 2010 David Rowe
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_CODEC2UTILS_H
+#define AVCODEC_CODEC2UTILS_H
+
+#include <stdint.h>
+
+#ifndef __CODEC2__
+//from codec2.h, repeated here to avoid a dependency
+#define CODEC2_MODE_3200 0
+#define CODEC2_MODE_2400 1
+#define CODEC2_MODE_1600 2
+#define CODEC2_MODE_1400 3
+#define CODEC2_MODE_1300 4
+#define CODEC2_MODE_1200 5
+#define CODEC2_MODE_700  6
+#define CODEC2_MODE_700B 7
+#define CODEC2_MODE_700C 8
+#endif
+
+#define AVPRIV_CODEC2_MAX_KNOWN_MODE CODEC2_MODE_700C
+
+//Converts strings like "1400" -> 3 and so on
+//logctx is used for av_log()
+//Returns <0 if modestr is invalid
+int avpriv_codec2_mode_from_str(void *logctx, const char *modestr);
+
+//The three following functions are here to avoid needing libavformat/codec2.c to depend on libcodec2
+
+//Computes bitrate from mode, with frames rounded up to the nearest octet.
+//So 700 bit/s (28 bits/frame) becomes 800 bits/s (32 bits/frame).
+//logctx is used for av_log()
+//Returns <0 if mode is invalid
+int avpriv_codec2_mode_bit_rate(void *logctx, int mode);
+
+//duplicates codec2_samples_per_frame()
+int avpriv_codec2_mode_frame_size(void *logctx, int mode);
+
+//duplicates (codec2_bits_per_frame()+7)/8
+int avpriv_codec2_mode_block_align(void *logctx, int mode);
+
+//Used as extradata
+typedef struct avpriv_codec2_header {
+    uint8_t magic[3];
+    uint8_t version_major;
+    uint8_t version_minor;
+    uint8_t mode;
+    uint8_t flags;
+} avpriv_codec2_header;
+
+//Used in codec2raw demuxer and libcodec2 encoder to make up .c2 headers
+static inline avpriv_codec2_header avpriv_codec2_make_header(int mode) {
+    avpriv_codec2_header header = {
+        .magic = {0xC0, 0xDE, 0xC2},
+        //version 0.8 as of 2017-08-02 (r3345)
+        .version_major = 0,
+        .version_minor = 8,
+        .mode = mode,
+        .flags = 0,
+    };
+    return header;
+}
+
+#endif /* AVCODEC_CODEC2UTILS_H */
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 6f43b68b83..b5f5c2d9d8 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -2657,6 +2657,13 @@  static const AVCodecDescriptor codec_descriptors[] = {
         .props     = AV_CODEC_PROP_LOSSY,
     },
     {
+        .id        = AV_CODEC_ID_CODEC2,
+        .type      = AVMEDIA_TYPE_AUDIO,
+        .name      = "codec2",
+        .long_name = NULL_IF_CONFIG_SMALL("codec2 (very low bitrate speech codec)"),
+        .props     = AV_CODEC_PROP_LOSSY,
+    },
+    {
         .id        = AV_CODEC_ID_G723_1,
         .type      = AVMEDIA_TYPE_AUDIO,
         .name      = "g723_1",
diff --git a/libavcodec/libcodec2.c b/libavcodec/libcodec2.c
new file mode 100644
index 0000000000..3feb60f2dc
--- /dev/null
+++ b/libavcodec/libcodec2.c
@@ -0,0 +1,196 @@ 
+/*
+ * codec2 encoder/decoder using libcodec2
+ * Copyright (c) 2017 Tomas Härdin
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <codec2/codec2.h>
+#include "avcodec.h"
+#include "libavutil/opt.h"
+#include "internal.h"
+#include "codec2utils.h"
+
+typedef struct {
+    const AVClass *class;
+    struct CODEC2 *codec;
+    char *mode;
+} LibCodec2Context;
+
+static const AVOption options[] = {
+    //not AV_OPT_FLAG_DECODING_PARAM since mode should come from the demuxer
+    //1300 (aka FreeDV 1600) is the most common mode on-the-air, default to it here as well
+    { "mode", "codec2 mode", offsetof(LibCodec2Context, mode), AV_OPT_TYPE_STRING, {.str = "1300"}, 0, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
+    { NULL },
+};
+
+static const AVClass codec2_class = {
+    .class_name = "libcodec2",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static av_cold int libcodec2_init_common(AVCodecContext *avctx)
+{
+    LibCodec2Context *c2 = avctx->priv_data;
+    int mode;
+
+    //take -mode if set
+    if (c2->mode) {
+        if ((mode = avpriv_codec2_mode_from_str(avctx, c2->mode)) < 0) {
+            return mode;
+        }
+
+        if (!(avctx->extradata = av_mallocz(sizeof(avpriv_codec2_header) + AV_INPUT_BUFFER_PADDING_SIZE))) {
+            return AVERROR(ENOMEM);
+        }
+
+        avctx->extradata_size = sizeof(avpriv_codec2_header);
+        *((avpriv_codec2_header*)avctx->extradata) = avpriv_codec2_make_header(mode);
+    } else {
+        if (avctx->extradata_size != sizeof(avpriv_codec2_header)) {
+            av_log(avctx, AV_LOG_ERROR, "must have exactly %zu bytes of extradata (got %i)\n",
+                   sizeof(avpriv_codec2_header), avctx->extradata_size);
+            return AVERROR_INVALIDDATA;
+        }
+
+        mode = ((avpriv_codec2_header*)avctx->extradata)->mode;
+    }
+
+    if (!(c2->codec = codec2_create(mode))) {
+        return AVERROR(ENOMEM);
+    }
+
+    avctx->frame_size = codec2_samples_per_frame(c2->codec);
+    avctx->block_align = (codec2_bits_per_frame(c2->codec) + 7) / 8;
+    codec2_set_natural_or_gray(c2->codec, 1);
+
+    return 0;
+}
+
+static av_cold int libcodec2_init_decoder(AVCodecContext *avctx)
+{
+    avctx->sample_rate      = 8000;
+    avctx->channels         = 1;
+    avctx->sample_fmt       = AV_SAMPLE_FMT_S16;
+    avctx->channel_layout   = AV_CH_LAYOUT_MONO;
+
+    return libcodec2_init_common(avctx);
+}
+
+static av_cold int libcodec2_init_encoder(AVCodecContext *avctx)
+{
+    //will need to be smarter once we get wideband support
+    if (avctx->sample_rate != 8000 ||
+        avctx->channels != 1 ||
+        avctx->sample_fmt != AV_SAMPLE_FMT_S16) {
+        av_log(avctx, AV_LOG_ERROR, "only 8 kHz 16-bit mono allowed\n");
+        return AVERROR(EINVAL);
+    }
+
+    return libcodec2_init_common(avctx);
+}
+
+static av_cold int libcodec2_close(AVCodecContext *avctx)
+{
+    LibCodec2Context *c2 = avctx->priv_data;
+
+    codec2_destroy(c2->codec);
+    return 0;
+}
+
+static int libcodec2_decode(AVCodecContext *avctx, void *data,
+                            int *got_frame_ptr, AVPacket *pkt)
+{
+    LibCodec2Context *c2 = avctx->priv_data;
+    AVFrame *frame = data;
+    int ret, nframes, i;
+    uint8_t *input;
+    int16_t *output;
+
+    nframes = pkt->size / avctx->block_align;
+    frame->nb_samples = avctx->frame_size * nframes;
+
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
+        return ret;
+    }
+
+    input  = pkt->data;
+    output = (int16_t *)frame->data[0];
+
+    for (i = 0; i < nframes; i++) {
+        codec2_decode(c2->codec, output, input);
+        input  += avctx->block_align;
+        output += avctx->frame_size;
+    }
+
+    if (nframes > 0) {
+        *got_frame_ptr = 1;
+    }
+
+    return nframes * avctx->block_align;
+}
+
+static int libcodec2_encode(AVCodecContext *avctx, AVPacket *avpkt,
+                            const AVFrame *frame, int *got_packet_ptr)
+{
+    LibCodec2Context *c2 = avctx->priv_data;
+    int16_t *samples = (int16_t *)frame->data[0];
+    int ret;
+
+    if ((ret = ff_alloc_packet2(avctx, avpkt, avctx->block_align, 0)) < 0) {
+        return ret;
+    }
+
+    codec2_encode(c2->codec, avpkt->data, samples);
+    *got_packet_ptr = 1;
+
+    return 0;
+}
+
+AVCodec ff_libcodec2_decoder = {
+    .name                   = "libcodec2",
+    .long_name              = NULL_IF_CONFIG_SMALL("codec2 decoder using libcodec2"),
+    .type                   = AVMEDIA_TYPE_AUDIO,
+    .id                     = AV_CODEC_ID_CODEC2,
+    .priv_data_size         = sizeof(LibCodec2Context),
+    .init                   = libcodec2_init_decoder,
+    .close                  = libcodec2_close,
+    .decode                 = libcodec2_decode,
+    .capabilities           = 0,
+    .supported_samplerates  = (const int[]){ 8000, 0 },
+    .sample_fmts            = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
+    .channel_layouts        = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
+    .priv_class             = &codec2_class,
+};
+
+AVCodec ff_libcodec2_encoder = {
+    .name                   = "libcodec2",
+    .long_name              = NULL_IF_CONFIG_SMALL("codec2 encoder using libcodec2"),
+    .type                   = AVMEDIA_TYPE_AUDIO,
+    .id                     = AV_CODEC_ID_CODEC2,
+    .priv_data_size         = sizeof(LibCodec2Context),
+    .init                   = libcodec2_init_encoder,
+    .close                  = libcodec2_close,
+    .encode2                = libcodec2_encode,
+    .capabilities           = 0,
+    .supported_samplerates  = (const int[]){ 8000, 0 },
+    .sample_fmts            = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
+    .channel_layouts        = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
+    .priv_class             = &codec2_class,
+};
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 02c4f41800..7473000579 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@ 
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  57
-#define LIBAVCODEC_VERSION_MINOR 102
+#define LIBAVCODEC_VERSION_MINOR 103
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavformat/Makefile b/libavformat/Makefile
index b0ef82cdd4..b1ae7a013d 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -128,6 +128,10 @@  OBJS-$(CONFIG_CAVSVIDEO_MUXER)           += rawenc.o
 OBJS-$(CONFIG_CDG_DEMUXER)               += cdg.o
 OBJS-$(CONFIG_CDXL_DEMUXER)              += cdxl.o
 OBJS-$(CONFIG_CINE_DEMUXER)              += cinedec.o
+OBJS-$(CONFIG_CODEC2_DEMUXER)            += codec2utils.o codec2.o rawdec.o pcm.o
+OBJS-$(CONFIG_CODEC2_MUXER)              += codec2utils.o codec2.o rawenc.o
+OBJS-$(CONFIG_CODEC2RAW_DEMUXER)         += codec2utils.o codec2.o rawdec.o pcm.o
+OBJS-$(CONFIG_CODEC2RAW_MUXER)           += rawenc.o
 OBJS-$(CONFIG_CONCAT_DEMUXER)            += concatdec.o
 OBJS-$(CONFIG_CRC_MUXER)                 += crcenc.o
 OBJS-$(CONFIG_DATA_DEMUXER)              += rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 1ebc14231c..26f0f1eccd 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -94,6 +94,8 @@  static void register_all(void)
     REGISTER_DEMUXER (CDG,              cdg);
     REGISTER_DEMUXER (CDXL,             cdxl);
     REGISTER_DEMUXER (CINE,             cine);
+    REGISTER_MUXDEMUX(CODEC2,           codec2);
+    REGISTER_MUXDEMUX(CODEC2RAW,        codec2raw);
     REGISTER_DEMUXER (CONCAT,           concat);
     REGISTER_MUXER   (CRC,              crc);
     REGISTER_MUXER   (DASH,             dash);
diff --git a/libavformat/codec2.c b/libavformat/codec2.c
new file mode 100644
index 0000000000..41dbf8c6f8
--- /dev/null
+++ b/libavformat/codec2.c
@@ -0,0 +1,289 @@ 
+/*
+ * codec2 raw demuxer
+ * Copyright (c) 2017 Tomas Härdin
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavcodec/codec2utils.h"
+#include "avio_internal.h"
+#include "avformat.h"
+#include "internal.h"
+#include "rawdec.h"
+#include "rawenc.h"
+#include "pcm.h"
+
+//the lowest version we should ever run across is 0.8
+//we may run across later versions as the format evolves
+#define EXPECTED_CODEC2_MAJOR_VERSION 0
+#define EXPECTED_CODEC2_MINOR_VERSION 8
+
+typedef struct {
+    const AVClass *class;
+    char *mode;
+} Codec2Context;
+
+//check for 0xC0DEC2, return non-zero if it doesn't match
+static int check_magic(uint8_t *ptr) {
+    return ptr[0] != 0xC0 || ptr[1] != 0xDE || ptr[2] != 0xC2;
+}
+
+static int codec2_probe(AVProbeData *p)
+{
+    int score;
+
+    //must be at least 7 bytes and start wih 0xC0DEC2
+    if (p->buf_size < sizeof(avpriv_codec2_header) || check_magic(p->buf)) {
+        return 0;
+    }
+
+    //no .c2 files prior to 0.8
+    if (p->buf[3] == 0 && p->buf[4] < 8) {
+        return 0;
+    }
+
+    //give a poor score if major version doesn't match
+    //this allows such files to be detected at least, even if we can't do much with them
+    if (p->buf[3] != EXPECTED_CODEC2_MAJOR_VERSION) {
+        return AVPROBE_SCORE_MAX/10;
+    }
+
+    //if the minor version is known, no unknown mode is used and no flags are set then -> max score,
+    //else penalize 20% for each byte outside of expectations
+    //this way if only the first four bytes are OK then we're slightly less than AVPROBE_SCORE_MAX/2
+    score = AVPROBE_SCORE_MAX;
+    if (p->buf[4] >  EXPECTED_CODEC2_MINOR_VERSION) score -= AVPROBE_SCORE_MAX/5;
+    if (p->buf[5] >  AVPRIV_CODEC2_MAX_KNOWN_MODE)  score -= AVPROBE_SCORE_MAX/5;
+    if (p->buf[6] != 0)                             score -= AVPROBE_SCORE_MAX/5;
+    return score;
+}
+
+static int codec2_read_header_common(AVFormatContext *s, AVStream *st)
+{
+    int mode = ((avpriv_codec2_header*)st->codecpar->extradata)->mode;
+
+    st->codecpar->codec_type        = AVMEDIA_TYPE_AUDIO;
+    st->codecpar->codec_id          = AV_CODEC_ID_CODEC2;
+    st->codecpar->sample_rate       = 8000;
+    st->codecpar->channels          = 1;
+    st->codecpar->format            = AV_SAMPLE_FMT_S16;
+    st->codecpar->channel_layout    = AV_CH_LAYOUT_MONO;
+    st->codecpar->bit_rate          = avpriv_codec2_mode_bit_rate(s, mode);
+    st->codecpar->frame_size        = avpriv_codec2_mode_frame_size(s, mode);
+    st->codecpar->block_align       = avpriv_codec2_mode_block_align(s, mode);
+
+    if (st->codecpar->bit_rate <= 0 ||
+        st->codecpar->frame_size <= 0 ||
+        st->codecpar->block_align <= 0) {
+        return AVERROR(EINVAL);
+    }
+
+    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+
+    //replicating estimate_timings_from_bit_rate() in utils.c to avoid warnings
+    if (s->pb && st->codecpar->bit_rate > 0) {
+        int64_t filesize = avio_size(s->pb);
+        if (filesize > s->internal->data_offset) {
+            filesize -= s->internal->data_offset;
+            st->duration = av_rescale(8 * filesize,
+                                      st->time_base.den,
+                                      st->codecpar->bit_rate * (int64_t) st->time_base.num);
+        }
+    }
+
+    return 0;
+}
+
+static int codec2_read_header(AVFormatContext *s)
+{
+    AVStream *st;
+    avpriv_codec2_header *header;
+
+    if (!(st = avformat_new_stream(s, NULL)) ||
+        ff_alloc_extradata(st->codecpar, sizeof(avpriv_codec2_header))) {
+        return AVERROR(ENOMEM);
+    }
+
+    s->internal->data_offset = sizeof(avpriv_codec2_header);
+    avio_read(s->pb, st->codecpar->extradata, sizeof(avpriv_codec2_header));
+    header = (avpriv_codec2_header*)st->codecpar->extradata;
+
+    if (check_magic(header->magic)) {
+        av_log(s, AV_LOG_ERROR, "not a .c2 file\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (header->version_major != EXPECTED_CODEC2_MAJOR_VERSION) {
+        avpriv_report_missing_feature(s, "Major version %i", header->version_major);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    return codec2_read_header_common(s, st);
+}
+
+//based off of ff_raw_read_partial_packet()
+static int codec2_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVStream *st = s->streams[0];
+    int ret, size, n, block_align, frame_size;
+
+    block_align = st->codecpar->block_align;
+    frame_size  = st->codecpar->frame_size;
+
+    if (block_align <= 0 || frame_size <= 0) {
+        return AVERROR(EINVAL);
+    }
+
+    //Read roughly 0.1 seconds worth of data.
+    n = st->codecpar->bit_rate / ((int)(8/0.1) * block_align) + 1;
+    size = n * block_align;
+
+    if (av_new_packet(pkt, size) < 0)
+        return AVERROR(ENOMEM);
+
+    //try to read desired number of bytes, recompute n from to actual number of bytes read
+    pkt->pos= avio_tell(s->pb);
+    pkt->stream_index = 0;
+    ret = avio_read(s->pb, pkt->data, size);
+    if (ret < 0) {
+        av_packet_unref(pkt);
+        return ret;
+    }
+
+    if (ret % block_align) {
+        av_log(s, AV_LOG_WARNING, "read partial frame, truncated file?\n");
+        ret -= ret % block_align;
+    }
+
+    av_shrink_packet(pkt, ret);
+    n = ret / block_align;
+
+    //only set duration - compute_pkt_fields() and ff_pcm_read_seek() takes care of everything else
+    //tested by spamming the seek functionality in ffplay
+    pkt->duration = n * frame_size;
+
+    return ret;
+}
+
+static int codec2_write_header(AVFormatContext *s)
+{
+    AVStream *st;
+
+    if (s->nb_streams != 1 || s->streams[0]->codecpar->codec_id != AV_CODEC_ID_CODEC2) {
+        av_log(s, AV_LOG_ERROR, ".c2 files must have exactly one codec2 stream\n");
+        return AVERROR(EINVAL);
+    }
+
+    st = s->streams[0];
+
+    if (st->codecpar->extradata_size != sizeof(avpriv_codec2_header)) {
+        av_log(s, AV_LOG_ERROR, ".c2 files require exactly %i bytes of extradata (got %i)\n",
+               (int)sizeof(avpriv_codec2_header), st->codecpar->extradata_size);
+        return AVERROR(EINVAL);
+    }
+
+    avio_write(s->pb, st->codecpar->extradata, sizeof(avpriv_codec2_header));
+
+    return 0;
+}
+
+static int codec2raw_read_header(AVFormatContext *s)
+{
+    Codec2Context *c2 = s->priv_data;
+    AVStream *st;
+    int mode;
+
+    if (!(st = avformat_new_stream(s, NULL)) ||
+        ff_alloc_extradata(st->codecpar, sizeof(avpriv_codec2_header))) {
+        return AVERROR(ENOMEM);
+    }
+
+    if ((mode = avpriv_codec2_mode_from_str(s, c2->mode)) < 0) {
+        return mode;
+    }
+
+    s->internal->data_offset = 0;
+    *((avpriv_codec2_header*)st->codecpar->extradata) = avpriv_codec2_make_header(mode);
+
+    return codec2_read_header_common(s, st);
+}
+
+static const AVOption options[] = {
+    { "mode", "codec2 mode", offsetof(Codec2Context, mode), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM},
+    { NULL },
+};
+
+static const AVClass codec2_class = {
+    .class_name = "codec2",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+    .category   = AV_CLASS_CATEGORY_DEMUXER,
+};
+
+static const AVClass codec2raw_class = {
+    .class_name = "codec2raw",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+    .category   = AV_CLASS_CATEGORY_DEMUXER,
+};
+
+#if CONFIG_CODEC2_DEMUXER
+AVInputFormat ff_codec2_demuxer = {
+    .name           = "codec2",
+    .long_name      = NULL_IF_CONFIG_SMALL("codec2 .c2 demuxer"),
+    .priv_data_size = sizeof(Codec2Context),
+    .extensions     = "c2",
+    .read_probe     = codec2_probe,
+    .read_header    = codec2_read_header,
+    .read_packet    = codec2_read_packet,
+    .read_seek      = ff_pcm_read_seek,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .raw_codec_id   = AV_CODEC_ID_CODEC2,
+    .priv_class     = &codec2_class,
+};
+#endif
+
+#if CONFIG_CODEC2_MUXER
+AVOutputFormat ff_codec2_muxer = {
+    .name           = "codec2",
+    .long_name      = NULL_IF_CONFIG_SMALL("codec2 .c2 muxer"),
+    .priv_data_size = sizeof(Codec2Context),
+    .extensions     = "c2",
+    .audio_codec    = AV_CODEC_ID_CODEC2,
+    .video_codec    = AV_CODEC_ID_NONE,
+    .write_header   = codec2_write_header,
+    .write_packet   = ff_raw_write_packet,
+    .flags          = AVFMT_NOTIMESTAMPS,
+    .priv_class     = &codec2_class,
+};
+#endif
+
+#if CONFIG_CODEC2RAW_DEMUXER
+AVInputFormat ff_codec2raw_demuxer = {
+    .name           = "codec2raw",
+    .long_name      = NULL_IF_CONFIG_SMALL("raw codec2 demuxer"),
+    .priv_data_size = sizeof(Codec2Context),
+    .read_header    = codec2raw_read_header,
+    .read_packet    = codec2_read_packet,
+    .read_seek      = ff_pcm_read_seek,
+    .flags          = AVFMT_GENERIC_INDEX,
+    .raw_codec_id   = AV_CODEC_ID_CODEC2,
+    .priv_class     = &codec2raw_class,
+};
+#endif
diff --git a/libavformat/rawenc.c b/libavformat/rawenc.c
index 26baa850e1..6ef22f21e3 100644
--- a/libavformat/rawenc.c
+++ b/libavformat/rawenc.c
@@ -104,6 +104,19 @@  AVOutputFormat ff_cavsvideo_muxer = {
 };
 #endif
 
+#if CONFIG_CODEC2RAW_MUXER
+AVOutputFormat ff_codec2raw_muxer = {
+    .name              = "codec2raw",
+    .long_name         = NULL_IF_CONFIG_SMALL("raw codec2 muxer"),
+    .audio_codec       = AV_CODEC_ID_CODEC2,
+    .video_codec       = AV_CODEC_ID_NONE,
+    .write_header      = force_one_stream,
+    .write_packet      = ff_raw_write_packet,
+    .flags             = AVFMT_NOTIMESTAMPS,
+};
+#endif
+
+
 #if CONFIG_DATA_MUXER
 AVOutputFormat ff_data_muxer = {
     .name              = "data",
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 38d247c6cd..3558e700ac 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -898,6 +898,7 @@  static int determinable_frame_size(AVCodecContext *avctx)
     case AV_CODEC_ID_MP1:
     case AV_CODEC_ID_MP2:
     case AV_CODEC_ID_MP3:
+    case AV_CODEC_ID_CODEC2:
         return 1;
     }
 
diff --git a/libavformat/version.h b/libavformat/version.h
index 48b81f2e48..a8cf4c158e 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,7 +32,7 @@ 
 // Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
 // Also please add any ticket numbers that you believe might be affected here
 #define LIBAVFORMAT_VERSION_MAJOR  57
-#define LIBAVFORMAT_VERSION_MINOR  76
+#define LIBAVFORMAT_VERSION_MINOR  77
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
-- 
2.13.3