[FFmpeg-devel,v24,3/9] avformat/evc_demuxer: Added demuxer to handle reading EVC video files

- Provided AVInputFormat struct describing EVC input format (ff_evc_demuxer)

Signed-off-by: Dawid Kozinski <d.kozinski@samsung.com>
---
 libavcodec/Makefile              |   1 +
 libavcodec/evc_frame_merge_bsf.c | 170 +++++++++++++++++++
 libavformat/Makefile             |   1 +
 libavformat/allformats.c         |   1 +
 libavformat/evcdec.c             | 276 +++++++++++++++++++++++++++++++
 5 files changed, 449 insertions(+)
 create mode 100644 libavcodec/evc_frame_merge_bsf.c
 create mode 100644 libavformat/evcdec.c

On Mon, Jun 12, 2023 at 2:29 PM Dawid Kozinski <d.kozinski@samsung.com>
wrote:

> - Provided AVInputFormat struct describing EVC input format
> (ff_evc_demuxer)
>
> Signed-off-by: Dawid Kozinski <d.kozinski@samsung.com>
> ---
>  libavcodec/Makefile              |   1 +
>  libavcodec/evc_frame_merge_bsf.c | 170 +++++++++++++++++++
>  libavformat/Makefile             |   1 +
>  libavformat/allformats.c         |   1 +
>  libavformat/evcdec.c             | 276 +++++++++++++++++++++++++++++++
>  5 files changed, 449 insertions(+)
>  create mode 100644 libavcodec/evc_frame_merge_bsf.c
>  create mode 100644 libavformat/evcdec.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 13e6582be3..376c6465cf 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -1257,6 +1257,7 @@ OBJS-$(CONFIG_VP9_METADATA_BSF)           +=
> vp9_metadata_bsf.o
>  OBJS-$(CONFIG_VP9_RAW_REORDER_BSF)        += vp9_raw_reorder_bsf.o
>  OBJS-$(CONFIG_VP9_SUPERFRAME_BSF)         += vp9_superframe_bsf.o
>  OBJS-$(CONFIG_VP9_SUPERFRAME_SPLIT_BSF)   += vp9_superframe_split_bsf.o
> +OBJS-$(CONFIG_EVC_FRAME_MERGE_BSF)        += evc_frame_merge_bsf.o
>
>  # thread libraries
>  OBJS-$(HAVE_LIBC_MSVCRT)               += file_open.o
> diff --git a/libavcodec/evc_frame_merge_bsf.c
> b/libavcodec/evc_frame_merge_bsf.c
> new file mode 100644
> index 0000000000..f7c4e18d76
> --- /dev/null
> +++ b/libavcodec/evc_frame_merge_bsf.c
> @@ -0,0 +1,170 @@
> +/*
> + * Copyright (c) 2019 James Almer <jamrial@gmail.com>
> + *
> + * 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 "get_bits.h"
> +#include "golomb.h"
> +#include "bsf.h"
> +#include "bsf_internal.h"
> +#include "avcodec.h"
> +
> +#include "evc.h"
> +#include "evc_parse.h"
> +
> +#define INIT_AU_BUF_CAPACITY 1024
> +
> +// Access unit data
> +typedef struct AccessUnitBuffer {
> +    uint8_t *data;      // the data buffer
> +    size_t data_size;   // size of data in bytes
> +    size_t capacity;    // buffer capacity
> +} AccessUnitBuffer;
> +
> +typedef struct EVCFMergeContext {
> +    AVPacket *in;
> +    EVCParserContext parser_ctx;
> +    AccessUnitBuffer au_buffer;
> +} EVCFMergeContext;
> +
> +static int end_of_access_unit_found(EVCParserContext *parser_ctx)
> +{
> +    if (parser_ctx->profile == 0) { // BASELINE profile
> +        if (parser_ctx->nalu_type == EVC_NOIDR_NUT ||
> parser_ctx->nalu_type == EVC_IDR_NUT)
> +            return 1;
> +    } else { // MAIN profile
> +        if (parser_ctx->nalu_type == EVC_NOIDR_NUT) {
> +            if (parser_ctx->poc.PicOrderCntVal !=
> parser_ctx->poc.prevPicOrderCntVal)
> +                return 1;
> +        } else if (parser_ctx->nalu_type == EVC_IDR_NUT)
> +            return 1;
> +    }
> +    return 0;
> +}
> +
> +static void evc_frame_merge_flush(AVBSFContext *bsf)
> +{
> +    EVCFMergeContext *ctx = bsf->priv_data;
> +
> +    av_packet_unref(ctx->in);
> +}
> +
> +static int evc_frame_merge_filter(AVBSFContext *bsf, AVPacket *out)
> +{
> +    EVCFMergeContext *ctx = bsf->priv_data;
> +    EVCParserContext *parser_ctx = &ctx->parser_ctx;
> +
> +    AVPacket *in = ctx->in;
> +
> +    int free_space = 0;
> +    size_t  nalu_size = 0;
> +    uint8_t *nalu = NULL;
> +    int au_end_found = 0;
> +    int err;
> +
> +    err = ff_bsf_get_packet_ref(bsf, in);
> +    if (err < 0)
> +        return err;
> +
> +    nalu_size = ff_evc_read_nal_unit_length(in->data,
> EVC_NALU_LENGTH_PREFIX_SIZE, bsf);
> +    if(nalu_size <= 0) {
>

Keep code style consistent. Here is missing space, ' '.

+        av_packet_unref(in);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    nalu = in->data + EVC_NALU_LENGTH_PREFIX_SIZE;
> +    nalu_size = in->size - EVC_NALU_LENGTH_PREFIX_SIZE;
> +
> +    // NAL unit parsing needed to determine if end of AU was found
> +    err = ff_evc_parse_nal_unit(parser_ctx, nalu, nalu_size, bsf);
> +    if (err < 0) {
> +        av_log(bsf, AV_LOG_ERROR, "NAL Unit parsing error\n");
> +        av_packet_unref(in);
> +
> +        return err;
> +    }
> +
> +    au_end_found = end_of_access_unit_found(parser_ctx);
> +
> +    free_space = ctx->au_buffer.capacity - ctx->au_buffer.data_size;
> +    while( free_space < in->size ) {
>

Wrong style, keep style consistent with already existing files in
libavformat.


> +        ctx->au_buffer.capacity *= 2;
> +        free_space = ctx->au_buffer.capacity - ctx->au_buffer.data_size;
> +
> +        if(free_space >= in->size)
> +            ctx->au_buffer.data = av_realloc(ctx->au_buffer.data,
> ctx->au_buffer.capacity);
> +    }
> +
> +    memcpy(ctx->au_buffer.data + ctx->au_buffer.data_size, in->data,
> in->size);
> +
> +    ctx->au_buffer.data_size += in->size;
> +
> +    av_packet_unref(in);
> +
> +    if(au_end_found) {
> +        uint8_t *data = av_memdup(ctx->au_buffer.data,
> ctx->au_buffer.data_size);
> +        err = av_packet_from_data(out, data, ctx->au_buffer.data_size);
> +
> +        ctx->au_buffer.data_size = 0;
> +    } else
> +        err = AVERROR(EAGAIN);
> +
> +    if (err < 0 && err != AVERROR(EAGAIN))
> +        evc_frame_merge_flush(bsf);
> +
> +    return err;
> +}
> +
> +static int evc_frame_merge_init(AVBSFContext *bsf)
> +{
> +    EVCFMergeContext *ctx = bsf->priv_data;
> +
> +    ctx->in  = av_packet_alloc();
> +    if (!ctx->in)
> +        return AVERROR(ENOMEM);
> +
> +    ctx->au_buffer.capacity = INIT_AU_BUF_CAPACITY;
> +    ctx->au_buffer.data = av_malloc(INIT_AU_BUF_CAPACITY);
> +    ctx->au_buffer.data_size = 0;
> +
> +    return 0;
> +}
> +
> +static void evc_frame_merge_close(AVBSFContext *bsf)
> +{
> +    EVCFMergeContext *ctx = bsf->priv_data;
> +
> +    av_packet_free(&ctx->in);
> +
> +    ctx->au_buffer.capacity = 0;
> +    av_freep(&ctx->au_buffer.data);
> +    ctx->au_buffer.data_size = 0;
> +}
> +
> +static const enum AVCodecID evc_frame_merge_codec_ids[] = {
> +    AV_CODEC_ID_EVC, AV_CODEC_ID_NONE,
> +};
> +
> +const FFBitStreamFilter ff_evc_frame_merge_bsf = {
> +    .p.name         = "evc_frame_merge",
> +    .p.codec_ids    = evc_frame_merge_codec_ids,
> +    .priv_data_size = sizeof(EVCFMergeContext),
> +    .init           = evc_frame_merge_init,
> +    .flush          = evc_frame_merge_flush,
> +    .close          = evc_frame_merge_close,
> +    .filter         = evc_frame_merge_filter,
> +};
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index f31135d806..6e4231fda2 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -251,6 +251,7 @@ OBJS-$(CONFIG_HCOM_DEMUXER)              += hcom.o
> pcm.o
>  OBJS-$(CONFIG_HDS_MUXER)                 += hdsenc.o
>  OBJS-$(CONFIG_HEVC_DEMUXER)              += hevcdec.o rawdec.o
>  OBJS-$(CONFIG_HEVC_MUXER)                += rawenc.o
> +OBJS-$(CONFIG_EVC_DEMUXER)               += evcdec.o rawdec.o
>  OBJS-$(CONFIG_EVC_MUXER)                 += rawenc.o
>  OBJS-$(CONFIG_HLS_DEMUXER)               += hls.o hls_sample_encryption.o
>  OBJS-$(CONFIG_HLS_MUXER)                 += hlsenc.o hlsplaylist.o avc.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index d3871de268..ae604236ae 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -154,6 +154,7 @@ extern const AVInputFormat  ff_ea_cdata_demuxer;
>  extern const AVInputFormat  ff_eac3_demuxer;
>  extern const FFOutputFormat ff_eac3_muxer;
>  extern const AVInputFormat  ff_epaf_demuxer;
> +extern const AVInputFormat  ff_evc_demuxer;
>  extern const FFOutputFormat ff_evc_muxer;
>  extern const FFOutputFormat ff_f4v_muxer;
>  extern const AVInputFormat  ff_ffmetadata_demuxer;
> diff --git a/libavformat/evcdec.c b/libavformat/evcdec.c
> new file mode 100644
> index 0000000000..89eda0f53e
> --- /dev/null
> +++ b/libavformat/evcdec.c
> @@ -0,0 +1,276 @@
> +/*
> + * RAW EVC video demuxer
> + *
> + * Copyright (c) 2021 Dawid Kozinski <d.kozinski@samsung.com>
> + *
> + * 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/get_bits.h"
> +#include "libavcodec/golomb.h"
> +#include "libavcodec/internal.h"
> +#include "libavcodec/evc.h"
> +#include "libavcodec/bsf.h"
> +
> +#include "libavutil/opt.h"
> +
> +#include "rawdec.h"
> +#include "avformat.h"
> +#include "internal.h"
> +
> +
> +#define RAW_PACKET_SIZE 1024
> +
> +typedef struct EVCParserContext {
> +    int got_sps;
> +    int got_pps;
> +    int got_idr;
> +    int got_nonidr;
> +
> +} EVCParserContext;
> +
> +typedef struct EVCDemuxContext {
> +    const AVClass *class;
> +    AVRational framerate;
> +
> +    AVBSFContext *bsf;
> +
> +} EVCDemuxContext;
> +
> +#define DEC AV_OPT_FLAG_DECODING_PARAM
> +#define OFFSET(x) offsetof(EVCDemuxContext, x)
> +static const AVOption evc_options[] = {
> +    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str =
> "25"}, 0, INT_MAX, DEC},
> +    { NULL },
> +};
> +#undef OFFSET
> +
> +static const AVClass evc_demuxer_class = {
> +    .class_name = "EVC Annex B demuxer",
> +    .item_name  = av_default_item_name,
> +    .option     = evc_options,
> +    .version    = LIBAVUTIL_VERSION_INT,
> +};
> +
> +static int get_nalu_type(const uint8_t *bits, int bits_size)
> +{
> +    int unit_type_plus1 = 0;
> +
> +    if (bits_size >= EVC_NALU_HEADER_SIZE) {
> +        unsigned char *p = (unsigned char *)bits;
> +        // forbidden_zero_bit
> +        if ((p[0] & 0x80) != 0)   // Cannot get bitstream information.
> Malformed bitstream.
> +            return -1;
> +
> +        // nal_unit_type
> +        unit_type_plus1 = (p[0] >> 1) & 0x3F;
> +    }
> +
> +    return unit_type_plus1 - 1;
> +}
> +
> +static uint32_t read_nal_unit_length(const uint8_t *bits, int bits_size)
> +{
> +    uint32_t nalu_len = 0;
> +
> +    if (bits_size >= EVC_NALU_LENGTH_PREFIX_SIZE) {
> +
> +        int t = 0;
> +        unsigned char *p = (unsigned char *)bits;
> +
> +        for (int i = 0; i < EVC_NALU_LENGTH_PREFIX_SIZE; i++)
> +            t = (t << 8) | p[i];
> +
> +        nalu_len = t;
> +        if (nalu_len == 0)   // Invalid bitstream size
> +            return 0;
> +    }
> +
> +    return nalu_len;
> +}
> +
> +static int parse_nal_units(const AVProbeData *p, EVCParserContext *ev)
> +{
> +    int nalu_type;
> +    size_t nalu_size;
> +    unsigned char *bits = (unsigned char *)p->buf;
> +    int bytes_to_read = p->buf_size;
> +
> +    while (bytes_to_read > EVC_NALU_LENGTH_PREFIX_SIZE) {
> +
> +        nalu_size = read_nal_unit_length(bits,
> EVC_NALU_LENGTH_PREFIX_SIZE);
> +        if (nalu_size == 0) break;
> +
> +        bits += EVC_NALU_LENGTH_PREFIX_SIZE;
> +        bytes_to_read -= EVC_NALU_LENGTH_PREFIX_SIZE;
> +
> +        if(bytes_to_read < nalu_size) break;
> +
> +        nalu_type = get_nalu_type(bits, bytes_to_read);
> +
> +        if (nalu_type == EVC_SPS_NUT)
> +            ev->got_sps++;
> +        else if (nalu_type == EVC_PPS_NUT)
> +            ev->got_pps++;
> +        else if (nalu_type == EVC_IDR_NUT )
> +            ev->got_idr++;
> +        else if (nalu_type == EVC_NOIDR_NUT)
> +            ev->got_nonidr++;
> +
> +        bits += nalu_size;
> +        bytes_to_read -= nalu_size;
> +    }
> +
> +    return 0;
> +}
> +
> +static int annexb_probe(const AVProbeData *p)
> +{
> +    EVCParserContext ev = {0};
> +    int ret = parse_nal_units(p, &ev);
> +
> +    if (ret == 0 && ev.got_sps && ev.got_pps && (ev.got_idr ||
> ev.got_nonidr > 3))
> +        return AVPROBE_SCORE_EXTENSION + 1;  // 1 more than .mpg
> +
> +    return 0;
> +}
> +
> +static int evc_read_header(AVFormatContext *s)
> +{
> +    AVStream *st;
> +    FFStream *sti;
> +    const AVBitStreamFilter *filter =
> av_bsf_get_by_name("evc_frame_merge");
> +    EVCDemuxContext *c = s->priv_data;
> +    int ret = 0;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st) {
> +        ret = AVERROR(ENOMEM);
> +        goto fail;
> +    }
> +    sti = ffstream(st);
> +
> +    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
> +    st->codecpar->codec_id = AV_CODEC_ID_EVC;
> +
> +    // This causes sending to the parser full frames, not chunks of data
> +    // The flag PARSER_FLAG_COMPLETE_FRAMES will be set in demux.c
> (demux.c: 1316)
> +    sti->need_parsing = AVSTREAM_PARSE_HEADERS;
> +
> +    st->avg_frame_rate = c->framerate;
> +    st->codecpar->framerate = c->framerate;
> +
> +    // taken from rawvideo demuxers
> +    avpriv_set_pts_info(st, 64, 1, 1200000);
> +
> +    ret = av_bsf_alloc(filter, &c->bsf);
> +    if (ret < 0)
> +        return ret;
> +
> +    ret = avcodec_parameters_copy(c->bsf->par_in, st->codecpar);
> +    if (ret < 0)
> +        return ret;
> +
> +    ret = av_bsf_init(c->bsf);
> +    if (ret < 0)
> +        return ret;
> +
> +fail:
> +    return ret;
> +}
> +
> +static int evc_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    int ret;
> +    int32_t nalu_size;
> +    int au_end_found;
> +
> +    EVCDemuxContext *const c = s->priv_data;
> +
> +    int eof = avio_feof (s->pb);
> +    if(eof) {
> +        av_packet_unref(pkt);
> +        return AVERROR_EOF;
> +    }
> +
> +    au_end_found = 0;
> +
> +    while(!au_end_found) {
> +
> +        uint8_t buf[EVC_NALU_LENGTH_PREFIX_SIZE];
> +        ret = avio_read(s->pb, (unsigned char *)&buf,
> EVC_NALU_LENGTH_PREFIX_SIZE);
> +        if (ret < 0) {
> +            av_packet_unref(pkt);
> +            return ret;
> +        }
> +
> +        nalu_size = read_nal_unit_length((const uint8_t *)&buf,
> EVC_NALU_LENGTH_PREFIX_SIZE);
> +        if(nalu_size <= 0) {
> +            av_packet_unref(pkt);
> +            return -1;
> +        }
> +
> +        avio_seek(s->pb, -EVC_NALU_LENGTH_PREFIX_SIZE, SEEK_CUR);
> +
> +        ret = av_get_packet(s->pb, pkt, nalu_size +
> EVC_NALU_LENGTH_PREFIX_SIZE);
> +        if (ret < 0)
> +            return ret;
> +        if (ret != (nalu_size + EVC_NALU_LENGTH_PREFIX_SIZE))
> +            return AVERROR(EIO);
> +
> +        ret = av_bsf_send_packet(c->bsf, pkt);
> +        if (ret < 0) {
> +            av_log(s, AV_LOG_ERROR, "Failed to send packet to "
> +                   "evc_frame_merge filter\n");
> +            return ret;
> +        }
> +
> +        ret = av_bsf_receive_packet(c->bsf, pkt);
> +        if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
> +            av_log(s, AV_LOG_ERROR, "evc_frame_merge filter failed to "
> +                   "send output packet\n");
> +
> +        au_end_found = 1;
> +        if (ret == AVERROR(EAGAIN))
> +            au_end_found = 0;
> +    }
> +
> +    return ret;
> +}
> +
> +static int evc_read_close(AVFormatContext *s)
> +{
> +    EVCDemuxContext *const c = s->priv_data;
> +
> +    av_bsf_free(&c->bsf);
> +    return 0;
> +}
> +
> +const AVInputFormat ff_evc_demuxer = {
> +    .name           = "evc",
> +    .long_name      = NULL_IF_CONFIG_SMALL("EVC Annex B"),
> +    .read_probe     = annexb_probe,
> +    .read_header    = evc_read_header, // annexb_read_header
> +    .read_packet    = evc_read_packet, // annexb_read_packet
> +    .read_close     = evc_read_close,
> +    .extensions     = "evc",
> +    .flags          = AVFMT_GENERIC_INDEX,
> +    .flags_internal = FF_FMT_INIT_CLEANUP,
> +    .raw_codec_id   = AV_CODEC_ID_EVC,
> +    .priv_data_size = sizeof(EVCDemuxContext),
> +    .priv_class     = &evc_demuxer_class,
> +};
> --
> 2.25.1
>
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