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/*
* 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 "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#define APM_FILE_HEADER_SIZE 18
#define APM_FILE_EXTRADATA_SIZE 80
#define APM_EXTRADATA_SIZE 28
#define APM_MAX_READ_SIZE 4096
#define APM_TAG_CODEC 0x2000
#define APM_TAG_VS12 MKTAG('v', 's', '1', '2')
#define APM_TAG_DATA MKTAG('D', 'A', 'T', 'A')
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 APMExtraData {
uint32_t magic;
uint32_t file_size;
uint32_t data_size;
uint32_t unk1;
uint32_t unk2;
APMState state;
uint32_t unk3[7];
uint32_t data;
} APMExtraData;
static void apm_parse_extradata(APMExtraData *ext, const uint8_t *buf)
{
ext->magic = AV_RL32(buf + 0);
ext->file_size = AV_RL32(buf + 4);
ext->data_size = AV_RL32(buf + 8);
ext->unk1 = AV_RL32(buf + 12);
ext->unk2 = AV_RL32(buf + 16);
ext->state.has_saved = AV_RL32(buf + 20);
ext->state.predictor_r = AV_RL32(buf + 24);
ext->state.step_index_r = AV_RL32(buf + 28);
ext->state.saved_r = AV_RL32(buf + 32);
ext->state.predictor_l = AV_RL32(buf + 36);
ext->state.step_index_l = AV_RL32(buf + 40);
ext->state.saved_l = AV_RL32(buf + 44);
for (int i = 0; i < FF_ARRAY_ELEMS(ext->unk3); i++)
ext->unk3[i] = AV_RL32(buf + 48 + (i * 4));
ext->data = AV_RL32(buf + 76);
}
static int apm_probe(const AVProbeData *p)
{
if (AV_RL16(p->buf) != APM_TAG_CODEC)
return 0;
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_MAX - 1;
}
static int apm_read_header(AVFormatContext *s)
{
int64_t ret;
AVStream *st;
APMExtraData extradata;
AVCodecParameters *par;
uint8_t buf[APM_FILE_EXTRADATA_SIZE];
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
/*
* This is 98% a WAVEFORMATEX, but there's something screwy with the extradata
* that ff_get_wav_header() can't (and shouldn't) handle properly.
*/
if (avio_rl16(s->pb) != APM_TAG_CODEC)
return AVERROR_INVALIDDATA;
par = st->codecpar;
par->channels = avio_rl16(s->pb);
par->sample_rate = avio_rl32(s->pb);
/* Skip the bitrate, it's usually wrong anyway. */
if ((ret = avio_skip(s->pb, 4)) < 0)
return ret;
par->block_align = avio_rl16(s->pb);
par->bits_per_coded_sample = avio_rl16(s->pb);
if (avio_rl32(s->pb) != APM_FILE_EXTRADATA_SIZE)
return AVERROR_INVALIDDATA;
/* 8 = bits per sample * max channels */
if (par->sample_rate > (INT_MAX / 8))
return AVERROR_INVALIDDATA;
if (par->bits_per_coded_sample != 4)
return AVERROR_INVALIDDATA;
if (par->channels == 2)
par->channel_layout = AV_CH_LAYOUT_STEREO;
else if (par->channels == 1)
par->channel_layout = AV_CH_LAYOUT_MONO;
else
return AVERROR_INVALIDDATA;
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
par->format = AV_SAMPLE_FMT_S16;
par->bits_per_raw_sample = 16;
par->bit_rate = par->channels *
par->sample_rate *
par->bits_per_coded_sample;
if ((ret = avio_read(s->pb, buf, APM_FILE_EXTRADATA_SIZE)) < 0)
return ret;
else if (ret != APM_FILE_EXTRADATA_SIZE)
return AVERROR(EIO);
apm_parse_extradata(&extradata, buf);
if (extradata.magic != APM_TAG_VS12 || extradata.data != APM_TAG_DATA)
return AVERROR_INVALIDDATA;
if (extradata.state.has_saved) {
avpriv_request_sample(s, "Saved Samples");
return AVERROR_PATCHWELCOME;
}
if ((ret = ff_alloc_extradata(par, APM_EXTRADATA_SIZE)) < 0)
return ret;
/* Use the entire state as extradata. */
memcpy(par->extradata, buf + 20, APM_EXTRADATA_SIZE);
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
st->start_time = 0;
st->duration = extradata.data_size *
(8 / par->bits_per_coded_sample) /
par->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_probe = apm_probe,
.read_header = apm_read_header,
.read_packet = apm_read_packet
};
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