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[FFmpeg-devel,2/2] avformat: add demuxer for Rayman 2's APM format

Message ID 20200217091257.9467-3-zane@zanevaniperen.com
State New
Headers show
Series Ubisoft Rayman 2 APM demuxer + decoder.
Related show

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Context Check Description
andriy/ffmpeg-patchwork pending
andriy/ffmpeg-patchwork success Applied patch
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andriy/ffmpeg-patchwork success Make finished
andriy/ffmpeg-patchwork success Make fate finished

Commit Message

Zane van Iperen Feb. 17, 2020, 9:13 a.m. UTC
Adds support for the APM file format used by Ubisoft's Rayman 2.

Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
---
 libavformat/Makefile     |   1 +
 libavformat/allformats.c |   1 +
 libavformat/apm.c        | 171 +++++++++++++++++++++++++++++++++++++++
 libavformat/version.h    |   2 +-
 4 files changed, 174 insertions(+), 1 deletion(-)
 create mode 100644 libavformat/apm.c

Comments

Paul B Mahol Feb. 17, 2020, 9:26 a.m. UTC | #1
On 2/17/20, Zane van Iperen <zane@zanevaniperen.com> wrote:
> Adds support for the APM file format used by Ubisoft's Rayman 2.
>
> Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
> ---
>  libavformat/Makefile     |   1 +
>  libavformat/allformats.c |   1 +
>  libavformat/apm.c        | 171 +++++++++++++++++++++++++++++++++++++++
>  libavformat/version.h    |   2 +-
>  4 files changed, 174 insertions(+), 1 deletion(-)
>  create mode 100644 libavformat/apm.c
>
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index a9972fd99a..e0681058a2 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -92,6 +92,7 @@ OBJS-$(CONFIG_AMRWB_DEMUXER)             += amr.o
>  OBJS-$(CONFIG_ANM_DEMUXER)               += anm.o
>  OBJS-$(CONFIG_APC_DEMUXER)               += apc.o
>  OBJS-$(CONFIG_APE_DEMUXER)               += ape.o apetag.o img2.o
> +OBJS-$(CONFIG_APM_DEMUXER)               += apm.o
>  OBJS-$(CONFIG_APNG_DEMUXER)              += apngdec.o
>  OBJS-$(CONFIG_APNG_MUXER)                += apngenc.o
>  OBJS-$(CONFIG_APTX_DEMUXER)              += aptxdec.o rawdec.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 3ea4100e85..0209bf0e30 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -53,6 +53,7 @@ extern AVInputFormat  ff_amrwb_demuxer;
>  extern AVInputFormat  ff_anm_demuxer;
>  extern AVInputFormat  ff_apc_demuxer;
>  extern AVInputFormat  ff_ape_demuxer;
> +extern AVInputFormat  ff_apm_demuxer;
>  extern AVInputFormat  ff_apng_demuxer;
>  extern AVOutputFormat ff_apng_muxer;
>  extern AVInputFormat  ff_aptx_demuxer;
> diff --git a/libavformat/apm.c b/libavformat/apm.c
> new file mode 100644
> index 0000000000..d13c2eda31
> --- /dev/null
> +++ b/libavformat/apm.c
> @@ -0,0 +1,171 @@
> +/*
> + * Rayman 2 APM Demuxer
> + *
> + * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.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 "avformat.h"
> +#include "internal.h"
> +#include "riff.h"
> +#include "libavutil/internal.h"
> +#include "libavutil/intreadwrite.h"
> +
> +#define APM_FILE_HEADER_SIZE    20
> +#define APM_VS12_CHUNK_SIZE     76
> +#define APM_MAX_READ_SIZE       4096
> +
> +typedef struct APMState {
> +    int32_t     has_saved;
> +    int32_t     predictor_r;
> +    int32_t     step_index_r;
> +    int32_t     saved_r;
> +    int32_t     predictor_l;
> +    int32_t     step_index_l;
> +    int32_t     saved_l;
> +} APMState;
> +
> +typedef struct APMVS12Chunk {
> +    uint32_t    magic;
> +    uint32_t    file_size;
> +    uint32_t    data_size;
> +    uint32_t    unk1;
> +    uint32_t    unk2;
> +    APMState    state;
> +    uint32_t    pad[7];
> +} APMVS12Chunk;
> +
> +static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
> +{
> +    vs12->magic                 = AV_RL32(buf + 0);
> +    vs12->file_size             = AV_RL32(buf + 4);
> +    vs12->data_size             = AV_RL32(buf + 8);
> +    vs12->unk1                  = AV_RL32(buf + 12);
> +    vs12->unk2                  = AV_RL32(buf + 16);
> +
> +    vs12->state.has_saved       = AV_RL32(buf + 20);
> +    vs12->state.predictor_r     = AV_RL32(buf + 24);
> +    vs12->state.step_index_r    = AV_RL32(buf + 28);
> +    vs12->state.saved_r         = AV_RL32(buf + 32);
> +    vs12->state.predictor_l     = AV_RL32(buf + 36);
> +    vs12->state.step_index_l    = AV_RL32(buf + 40);
> +    vs12->state.saved_l         = AV_RL32(buf + 44);
> +
> +    for (int i = 0; i < FF_ARRAY_ELEMS(vs12->pad); i++)
> +        vs12->pad[i]            = AV_RL32(buf + 48 + (i * 4));
> +}
> +
> +static int apm_read_header(AVFormatContext *s)
> +{
> +    int64_t ret;
> +    AVStream *st;
> +    APMVS12Chunk vs12;
> +    uint8_t buf[APM_VS12_CHUNK_SIZE];
> +
> +    if (!(st = avformat_new_stream(s, NULL)))
> +        return AVERROR(ENOMEM);
> +
> +    /* The header starts with a WAVEFORMATEX */
> +    if ((ret = ff_get_wav_header(s, s->pb, st->codecpar,
> APM_FILE_HEADER_SIZE, 0)) < 0)
> +        return ret;
> +
> +    if (st->codecpar->bits_per_coded_sample != 4)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (st->codecpar->codec_tag != 0x2000)
> +        return AVERROR_INVALIDDATA;
> +
> +    /* ff_get_wav_header() does most of the work, but we need to fix a few
> things. */
> +    st->codecpar->codec_id              = AV_CODEC_ID_ADPCM_IMA_APM;
> +    st->codecpar->codec_tag             = 0;
> +
> +    if (st->codecpar->channels == 2)
> +        st->codecpar->channel_layout    = AV_CH_LAYOUT_STEREO;
> +    else if (st->codecpar->channels == 1)
> +        st->codecpar->channel_layout    = AV_CH_LAYOUT_MONO;
> +    else
> +        return AVERROR_INVALIDDATA;
> +
> +    st->codecpar->format                = AV_SAMPLE_FMT_S16P;
> +    st->codecpar->bits_per_raw_sample   = 16;
> +    st->codecpar->bit_rate              = st->codecpar->channels *
> +                                          st->codecpar->sample_rate *
> +
> st->codecpar->bits_per_coded_sample;
> +
> +    if ((ret = avio_read(s->pb, buf, APM_VS12_CHUNK_SIZE)) < 0)
> +        return ret;
> +    else if (ret != APM_VS12_CHUNK_SIZE)
> +        return AVERROR(EIO);
> +
> +    apm_parse_vs12(&vs12, buf);
> +
> +    if (vs12.magic != MKTAG('v', 's', '1', '2')) {
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (vs12.state.has_saved) {
> +        avpriv_request_sample(s, "Saved Samples");
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
> +    if (avio_rl32(s->pb) != MKTAG('D', 'A', 'T', 'A'))
> +        return AVERROR_INVALIDDATA;
> +
> +    if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0)
> +        return ret;
> +
> +    AV_WN32(st->codecpar->extradata +  0, vs12.state.predictor_l);
> +    AV_WN32(st->codecpar->extradata +  4, vs12.state.step_index_l);
> +    AV_WN32(st->codecpar->extradata +  8, vs12.state.predictor_r);
> +    AV_WN32(st->codecpar->extradata + 12, vs12.state.step_index_r);

Use same endianess as it is written in file.

> +
> +    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
> +    st->start_time  = 0;
> +    st->duration    = vs12.data_size *
> +                      (8 / st->codecpar->bits_per_coded_sample) /
> +                      st->codecpar->channels;
> +    return 0;
> +}
> +
> +static int apm_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    int ret;
> +    AVCodecParameters *par = s->streams[0]->codecpar;
> +
> +    /*
> +     * For future reference: if files with the `has_saved` field set ever
> +     * surface, `saved_l`, and `saved_r` will each contain 8 "saved"
> samples
> +     * that should be sent to the decoder before the actual data.
> +     */
> +
> +    if ((ret = av_get_packet(s->pb, pkt, APM_MAX_READ_SIZE)) < 0)
> +        return ret;
> +
> +    pkt->flags          &= ~AV_PKT_FLAG_CORRUPT;
> +    pkt->stream_index   = 0;
> +    pkt->duration       = ret * (8 / par->bits_per_coded_sample) /
> par->channels;
> +
> +    return 0;
> +}
> +
> +AVInputFormat ff_apm_demuxer = {
> +    .name           = "apm",
> +    .long_name      = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
> +    .read_header    = apm_read_header,
> +    .read_packet    = apm_read_packet,
> +    .extensions     = "apm"

Also add probe function.

> +};
> diff --git a/libavformat/version.h b/libavformat/version.h
> index 94fa57614d..4724269b3c 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  58
> -#define LIBAVFORMAT_VERSION_MINOR  38
> +#define LIBAVFORMAT_VERSION_MINOR  39
>  #define LIBAVFORMAT_VERSION_MICRO 101

Reset micro to 0, when changing minor.


>
>  #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
> --
> 2.17.1
>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Zane van Iperen Feb. 17, 2020, 9:49 a.m. UTC | #2
On 17/2/20 7:26 pm, Paul B Mahol wrote:
> 
> On 2/17/20, Zane van Iperen <zane@zanevaniperen.com> wrote:
>> Adds support for the APM file format used by Ubisoft's Rayman 2.
>>
>> Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
>> ---
>>   libavformat/Makefile     |   1 +
>>   libavformat/allformats.c |   1 +
>>   libavformat/apm.c        | 171 +++++++++++++++++++++++++++++++++++++++
>>   libavformat/version.h    |   2 +-
>>   4 files changed, 174 insertions(+), 1 deletion(-)
>>   create mode 100644 libavformat/apm.c
>>
>> diff --git a/libavformat/Makefile b/libavformat/Makefile
>> index a9972fd99a..e0681058a2 100644
>> --- a/libavformat/Makefile
>> +++ b/libavformat/Makefile
>> @@ -92,6 +92,7 @@ OBJS-$(CONFIG_AMRWB_DEMUXER)             += amr.o
>>   OBJS-$(CONFIG_ANM_DEMUXER)               += anm.o
>>   OBJS-$(CONFIG_APC_DEMUXER)               += apc.o
>>   OBJS-$(CONFIG_APE_DEMUXER)               += ape.o apetag.o img2.o
>> +OBJS-$(CONFIG_APM_DEMUXER)               += apm.o
>>   OBJS-$(CONFIG_APNG_DEMUXER)              += apngdec.o
>>   OBJS-$(CONFIG_APNG_MUXER)                += apngenc.o
>>   OBJS-$(CONFIG_APTX_DEMUXER)              += aptxdec.o rawdec.o
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index 3ea4100e85..0209bf0e30 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -53,6 +53,7 @@ extern AVInputFormat  ff_amrwb_demuxer;
>>   extern AVInputFormat  ff_anm_demuxer;
>>   extern AVInputFormat  ff_apc_demuxer;
>>   extern AVInputFormat  ff_ape_demuxer;
>> +extern AVInputFormat  ff_apm_demuxer;
>>   extern AVInputFormat  ff_apng_demuxer;
>>   extern AVOutputFormat ff_apng_muxer;
>>   extern AVInputFormat  ff_aptx_demuxer;
>> diff --git a/libavformat/apm.c b/libavformat/apm.c
>> new file mode 100644
>> index 0000000000..d13c2eda31
>> --- /dev/null
>> +++ b/libavformat/apm.c
>> @@ -0,0 +1,171 @@
>> +/*
>> + * Rayman 2 APM Demuxer
>> + *
>> + * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.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 "avformat.h"
>> +#include "internal.h"
>> +#include "riff.h"
>> +#include "libavutil/internal.h"
>> +#include "libavutil/intreadwrite.h"
>> +
>> +#define APM_FILE_HEADER_SIZE    20
>> +#define APM_VS12_CHUNK_SIZE     76
>> +#define APM_MAX_READ_SIZE       4096
>> +
>> +typedef struct APMState {
>> +    int32_t     has_saved;
>> +    int32_t     predictor_r;
>> +    int32_t     step_index_r;
>> +    int32_t     saved_r;
>> +    int32_t     predictor_l;
>> +    int32_t     step_index_l;
>> +    int32_t     saved_l;
>> +} APMState;
>> +
>> +typedef struct APMVS12Chunk {
>> +    uint32_t    magic;
>> +    uint32_t    file_size;
>> +    uint32_t    data_size;
>> +    uint32_t    unk1;
>> +    uint32_t    unk2;
>> +    APMState    state;
>> +    uint32_t    pad[7];
>> +} APMVS12Chunk;
>> +
>> +static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
>> +{
>> +    vs12->magic                 = AV_RL32(buf + 0);
>> +    vs12->file_size             = AV_RL32(buf + 4);
>> +    vs12->data_size             = AV_RL32(buf + 8);
>> +    vs12->unk1                  = AV_RL32(buf + 12);
>> +    vs12->unk2                  = AV_RL32(buf + 16);
>> +
>> +    vs12->state.has_saved       = AV_RL32(buf + 20);
>> +    vs12->state.predictor_r     = AV_RL32(buf + 24);
>> +    vs12->state.step_index_r    = AV_RL32(buf + 28);
>> +    vs12->state.saved_r         = AV_RL32(buf + 32);
>> +    vs12->state.predictor_l     = AV_RL32(buf + 36);
>> +    vs12->state.step_index_l    = AV_RL32(buf + 40);
>> +    vs12->state.saved_l         = AV_RL32(buf + 44);
>> +
>> +    for (int i = 0; i < FF_ARRAY_ELEMS(vs12->pad); i++)
>> +        vs12->pad[i]            = AV_RL32(buf + 48 + (i * 4));
>> +}
>> +
>> +static int apm_read_header(AVFormatContext *s)
>> +{
>> +    int64_t ret;
>> +    AVStream *st;
>> +    APMVS12Chunk vs12;
>> +    uint8_t buf[APM_VS12_CHUNK_SIZE];
>> +
>> +    if (!(st = avformat_new_stream(s, NULL)))
>> +        return AVERROR(ENOMEM);
>> +
>> +    /* The header starts with a WAVEFORMATEX */
>> +    if ((ret = ff_get_wav_header(s, s->pb, st->codecpar,
>> APM_FILE_HEADER_SIZE, 0)) < 0)
>> +        return ret;
>> +
>> +    if (st->codecpar->bits_per_coded_sample != 4)
>> +        return AVERROR_INVALIDDATA;
>> +
>> +    if (st->codecpar->codec_tag != 0x2000)
>> +        return AVERROR_INVALIDDATA;
>> +
>> +    /* ff_get_wav_header() does most of the work, but we need to fix a few
>> things. */
>> +    st->codecpar->codec_id              = AV_CODEC_ID_ADPCM_IMA_APM;
>> +    st->codecpar->codec_tag             = 0;
>> +
>> +    if (st->codecpar->channels == 2)
>> +        st->codecpar->channel_layout    = AV_CH_LAYOUT_STEREO;
>> +    else if (st->codecpar->channels == 1)
>> +        st->codecpar->channel_layout    = AV_CH_LAYOUT_MONO;
>> +    else
>> +        return AVERROR_INVALIDDATA;
>> +
>> +    st->codecpar->format                = AV_SAMPLE_FMT_S16P;
>> +    st->codecpar->bits_per_raw_sample   = 16;
>> +    st->codecpar->bit_rate              = st->codecpar->channels *
>> +                                          st->codecpar->sample_rate *
>> +
>> st->codecpar->bits_per_coded_sample;
>> +
>> +    if ((ret = avio_read(s->pb, buf, APM_VS12_CHUNK_SIZE)) < 0)
>> +        return ret;
>> +    else if (ret != APM_VS12_CHUNK_SIZE)
>> +        return AVERROR(EIO);
>> +
>> +    apm_parse_vs12(&vs12, buf);
>> +
>> +    if (vs12.magic != MKTAG('v', 's', '1', '2')) {
>> +        return AVERROR_INVALIDDATA;
>> +    }
>> +
>> +    if (vs12.state.has_saved) {
>> +        avpriv_request_sample(s, "Saved Samples");
>> +        return AVERROR_PATCHWELCOME;
>> +    }
>> +
>> +    if (avio_rl32(s->pb) != MKTAG('D', 'A', 'T', 'A'))
>> +        return AVERROR_INVALIDDATA;
>> +
>> +    if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0)
>> +        return ret;
>> +
>> +    AV_WN32(st->codecpar->extradata +  0, vs12.state.predictor_l);
>> +    AV_WN32(st->codecpar->extradata +  4, vs12.state.step_index_l);
>> +    AV_WN32(st->codecpar->extradata +  8, vs12.state.predictor_r);
>> +    AV_WN32(st->codecpar->extradata + 12, vs12.state.step_index_r);
> 
> Use same endianess as it is written in file.
> 

Fixed (and in the codec too).

>> +
>> +    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
>> +    st->start_time  = 0;
>> +    st->duration    = vs12.data_size *
>> +                      (8 / st->codecpar->bits_per_coded_sample) /
>> +                      st->codecpar->channels;
>> +    return 0;
>> +}
>> +
>> +static int apm_read_packet(AVFormatContext *s, AVPacket *pkt)
>> +{
>> +    int ret;
>> +    AVCodecParameters *par = s->streams[0]->codecpar;
>> +
>> +    /*
>> +     * For future reference: if files with the `has_saved` field set ever
>> +     * surface, `saved_l`, and `saved_r` will each contain 8 "saved"
>> samples
>> +     * that should be sent to the decoder before the actual data.
>> +     */
>> +
>> +    if ((ret = av_get_packet(s->pb, pkt, APM_MAX_READ_SIZE)) < 0)
>> +        return ret;
>> +
>> +    pkt->flags          &= ~AV_PKT_FLAG_CORRUPT;
>> +    pkt->stream_index   = 0;
>> +    pkt->duration       = ret * (8 / par->bits_per_coded_sample) /
>> par->channels;
>> +
>> +    return 0;
>> +}
>> +
>> +AVInputFormat ff_apm_demuxer = {
>> +    .name           = "apm",
>> +    .long_name      = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
>> +    .read_header    = apm_read_header,
>> +    .read_packet    = apm_read_packet,
>> +    .extensions     = "apm"
> 
> Also add probe function.

There's no real "magic" fields to look for, hence why I set the `extensions`
field. What would a probe function do in this case?

> 
>> +};
>> diff --git a/libavformat/version.h b/libavformat/version.h
>> index 94fa57614d..4724269b3c 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  58
>> -#define LIBAVFORMAT_VERSION_MINOR  38
>> +#define LIBAVFORMAT_VERSION_MINOR  39
>>   #define LIBAVFORMAT_VERSION_MICRO 101
> 
> Reset micro to 0, when changing minor.
> 
> 

Gah, knew I'd forgotten something simple. Fixed.

>>
>>   #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
>> --
>> 2.17.1
>>
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

Zane
Carl Eugen Hoyos Feb. 17, 2020, 5:34 p.m. UTC | #3
Am 17.02.2020 um 10:49 schrieb Zane van Iperen <zane@zanevaniperen.com>:

>> 
>> Also add probe function.
> 
> 
> There's no real "magic" fields to look for, hence why I set the `extensions`
> field. What would a probe function do in this case?

I cannot look at the files right now:
Is there nothing that allows to distinguish them from random data?

Carl Eugen
Moritz Barsnick Feb. 17, 2020, 10:54 p.m. UTC | #4
On Mon, Feb 17, 2020 at 18:34:34 +0100, Carl Eugen Hoyos wrote:
> Am 17.02.2020 um 10:49 schrieb Zane van Iperen <zane@zanevaniperen.com>:
> > There's no real "magic" fields to look for, hence why I set the `extensions`
> > field. What would a probe function do in this case?
>
> I cannot look at the files right now:
> Is there nothing that allows to distinguish them from random data?

I wonder too why there should be no magic data. The header function
already checks

+    if (vs12.magic != MKTAG('v', 's', '1', '2')) {

and

+    if (avio_rl32(s->pb) != MKTAG('D', 'A', 'T', 'A'))

Is this not magic? Is it not unique? Or at least a good hit justifying
some score?

Moritz
Zane van Iperen Feb. 17, 2020, 11:20 p.m. UTC | #5
On 18/2/20 8:54 am, Moritz Barsnick wrote:
> 
> On Mon, Feb 17, 2020 at 18:34:34 +0100, Carl Eugen Hoyos wrote:
>> Am 17.02.2020 um 10:49 schrieb Zane van Iperen <zane@zanevaniperen.com>:
>>> There's no real "magic" fields to look for, hence why I set the `extensions`
>>> field. What would a probe function do in this case?
>>
>> I cannot look at the files right now:
>> Is there nothing that allows to distinguish them from random data?
> 
> I wonder too why there should be no magic data. The header function
> already checks
> 
> +    if (vs12.magic != MKTAG('v', 's', '1', '2')) {
> 
> and
> 
> +    if (avio_rl32(s->pb) != MKTAG('D', 'A', 'T', 'A'))
> 
> Is this not magic? Is it not unique? Or at least a good hit justifying
> some score?
> 

So, something like this?

#define APM_TAG_VS12  MKTAG('v', 's', '1', '2')
#define APM_TAG_DATA  MKTAG('D', 'A', 'T', 'A')

static int apm_probe(const AVProbeData *p)
{
     if (p->buf_size < 100)
         return 0;

     if (AV_RL32(p->buf + 20) != APM_TAG_VS12)
         return 0;

     if (AV_RL32(p->buf + 96) != APM_TAG_DATA)
         return 0;

     return AVPROBE_SCORE_EXTENSION + 1;
}

> Moritz
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> 

Zane
Carl Eugen Hoyos Feb. 18, 2020, 6:16 a.m. UTC | #6
> Am 18.02.2020 um 00:20 schrieb Zane van Iperen <zane@zanevaniperen.com>:
> 
> So, something like this?
> 
> #define APM_TAG_VS12  MKTAG('v', 's', '1', '2')
> #define APM_TAG_DATA  MKTAG('D', 'A', 'T', 'A')
> 
> static int apm_probe(const AVProbeData *p)
> {
>     if (p->buf_size < 100)
>         return 0;
> 
>     if (AV_RL32(p->buf + 20) != APM_TAG_VS12)
>         return 0;
> 
>     if (AV_RL32(p->buf + 96) != APM_TAG_DATA)
>         return 0;
> 
>     return AVPROBE_SCORE_EXTENSION + 1;

Yes but you can increase the score for 64 matching bits to MAX-1

Thank you, Carl Eugen
diff mbox series

Patch

diff --git a/libavformat/Makefile b/libavformat/Makefile
index a9972fd99a..e0681058a2 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -92,6 +92,7 @@  OBJS-$(CONFIG_AMRWB_DEMUXER)             += amr.o
 OBJS-$(CONFIG_ANM_DEMUXER)               += anm.o
 OBJS-$(CONFIG_APC_DEMUXER)               += apc.o
 OBJS-$(CONFIG_APE_DEMUXER)               += ape.o apetag.o img2.o
+OBJS-$(CONFIG_APM_DEMUXER)               += apm.o
 OBJS-$(CONFIG_APNG_DEMUXER)              += apngdec.o
 OBJS-$(CONFIG_APNG_MUXER)                += apngenc.o
 OBJS-$(CONFIG_APTX_DEMUXER)              += aptxdec.o rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 3ea4100e85..0209bf0e30 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -53,6 +53,7 @@  extern AVInputFormat  ff_amrwb_demuxer;
 extern AVInputFormat  ff_anm_demuxer;
 extern AVInputFormat  ff_apc_demuxer;
 extern AVInputFormat  ff_ape_demuxer;
+extern AVInputFormat  ff_apm_demuxer;
 extern AVInputFormat  ff_apng_demuxer;
 extern AVOutputFormat ff_apng_muxer;
 extern AVInputFormat  ff_aptx_demuxer;
diff --git a/libavformat/apm.c b/libavformat/apm.c
new file mode 100644
index 0000000000..d13c2eda31
--- /dev/null
+++ b/libavformat/apm.c
@@ -0,0 +1,171 @@ 
+/*
+ * Rayman 2 APM Demuxer
+ *
+ * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.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 "avformat.h"
+#include "internal.h"
+#include "riff.h"
+#include "libavutil/internal.h"
+#include "libavutil/intreadwrite.h"
+
+#define APM_FILE_HEADER_SIZE    20
+#define APM_VS12_CHUNK_SIZE     76
+#define APM_MAX_READ_SIZE       4096
+
+typedef struct APMState {
+    int32_t     has_saved;
+    int32_t     predictor_r;
+    int32_t     step_index_r;
+    int32_t     saved_r;
+    int32_t     predictor_l;
+    int32_t     step_index_l;
+    int32_t     saved_l;
+} APMState;
+
+typedef struct APMVS12Chunk {
+    uint32_t    magic;
+    uint32_t    file_size;
+    uint32_t    data_size;
+    uint32_t    unk1;
+    uint32_t    unk2;
+    APMState    state;
+    uint32_t    pad[7];
+} APMVS12Chunk;
+
+static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
+{
+    vs12->magic                 = AV_RL32(buf + 0);
+    vs12->file_size             = AV_RL32(buf + 4);
+    vs12->data_size             = AV_RL32(buf + 8);
+    vs12->unk1                  = AV_RL32(buf + 12);
+    vs12->unk2                  = AV_RL32(buf + 16);
+
+    vs12->state.has_saved       = AV_RL32(buf + 20);
+    vs12->state.predictor_r     = AV_RL32(buf + 24);
+    vs12->state.step_index_r    = AV_RL32(buf + 28);
+    vs12->state.saved_r         = AV_RL32(buf + 32);
+    vs12->state.predictor_l     = AV_RL32(buf + 36);
+    vs12->state.step_index_l    = AV_RL32(buf + 40);
+    vs12->state.saved_l         = AV_RL32(buf + 44);
+
+    for (int i = 0; i < FF_ARRAY_ELEMS(vs12->pad); i++)
+        vs12->pad[i]            = AV_RL32(buf + 48 + (i * 4));
+}
+
+static int apm_read_header(AVFormatContext *s)
+{
+    int64_t ret;
+    AVStream *st;
+    APMVS12Chunk vs12;
+    uint8_t buf[APM_VS12_CHUNK_SIZE];
+
+    if (!(st = avformat_new_stream(s, NULL)))
+        return AVERROR(ENOMEM);
+
+    /* The header starts with a WAVEFORMATEX */
+    if ((ret = ff_get_wav_header(s, s->pb, st->codecpar, APM_FILE_HEADER_SIZE, 0)) < 0)
+        return ret;
+
+    if (st->codecpar->bits_per_coded_sample != 4)
+        return AVERROR_INVALIDDATA;
+
+    if (st->codecpar->codec_tag != 0x2000)
+        return AVERROR_INVALIDDATA;
+
+    /* ff_get_wav_header() does most of the work, but we need to fix a few things. */
+    st->codecpar->codec_id              = AV_CODEC_ID_ADPCM_IMA_APM;
+    st->codecpar->codec_tag             = 0;
+
+    if (st->codecpar->channels == 2)
+        st->codecpar->channel_layout    = AV_CH_LAYOUT_STEREO;
+    else if (st->codecpar->channels == 1)
+        st->codecpar->channel_layout    = AV_CH_LAYOUT_MONO;
+    else
+        return AVERROR_INVALIDDATA;
+
+    st->codecpar->format                = AV_SAMPLE_FMT_S16P;
+    st->codecpar->bits_per_raw_sample   = 16;
+    st->codecpar->bit_rate              = st->codecpar->channels *
+                                          st->codecpar->sample_rate *
+                                          st->codecpar->bits_per_coded_sample;
+
+    if ((ret = avio_read(s->pb, buf, APM_VS12_CHUNK_SIZE)) < 0)
+        return ret;
+    else if (ret != APM_VS12_CHUNK_SIZE)
+        return AVERROR(EIO);
+
+    apm_parse_vs12(&vs12, buf);
+
+    if (vs12.magic != MKTAG('v', 's', '1', '2')) {
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (vs12.state.has_saved) {
+        avpriv_request_sample(s, "Saved Samples");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (avio_rl32(s->pb) != MKTAG('D', 'A', 'T', 'A'))
+        return AVERROR_INVALIDDATA;
+
+    if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0)
+        return ret;
+
+    AV_WN32(st->codecpar->extradata +  0, vs12.state.predictor_l);
+    AV_WN32(st->codecpar->extradata +  4, vs12.state.step_index_l);
+    AV_WN32(st->codecpar->extradata +  8, vs12.state.predictor_r);
+    AV_WN32(st->codecpar->extradata + 12, vs12.state.step_index_r);
+
+    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+    st->start_time  = 0;
+    st->duration    = vs12.data_size *
+                      (8 / st->codecpar->bits_per_coded_sample) /
+                      st->codecpar->channels;
+    return 0;
+}
+
+static int apm_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    int ret;
+    AVCodecParameters *par = s->streams[0]->codecpar;
+
+    /*
+     * For future reference: if files with the `has_saved` field set ever
+     * surface, `saved_l`, and `saved_r` will each contain 8 "saved" samples
+     * that should be sent to the decoder before the actual data.
+     */
+
+    if ((ret = av_get_packet(s->pb, pkt, APM_MAX_READ_SIZE)) < 0)
+        return ret;
+
+    pkt->flags          &= ~AV_PKT_FLAG_CORRUPT;
+    pkt->stream_index   = 0;
+    pkt->duration       = ret * (8 / par->bits_per_coded_sample) / par->channels;
+
+    return 0;
+}
+
+AVInputFormat ff_apm_demuxer = {
+    .name           = "apm",
+    .long_name      = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
+    .read_header    = apm_read_header,
+    .read_packet    = apm_read_packet,
+    .extensions     = "apm"
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 94fa57614d..4724269b3c 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  58
-#define LIBAVFORMAT_VERSION_MINOR  38
+#define LIBAVFORMAT_VERSION_MINOR  39
 #define LIBAVFORMAT_VERSION_MICRO 101
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \