| /* |
| * 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 |
| |
| #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 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_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_MAX - 1; |
| } |
| |
| 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_S16; |
| 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 != APM_TAG_VS12) { |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (vs12.state.has_saved) { |
| avpriv_request_sample(s, "Saved Samples"); |
| return AVERROR_PATCHWELCOME; |
| } |
| |
| if (avio_rl32(s->pb) != APM_TAG_DATA) |
| return AVERROR_INVALIDDATA; |
| |
| if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0) |
| return ret; |
| |
| AV_WL32(st->codecpar->extradata + 0, vs12.state.predictor_l); |
| AV_WL32(st->codecpar->extradata + 4, vs12.state.step_index_l); |
| AV_WL32(st->codecpar->extradata + 8, vs12.state.predictor_r); |
| AV_WL32(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_probe = apm_probe, |
| .read_header = apm_read_header, |
| .read_packet = apm_read_packet |
| }; |