libavformat/apm.c

   1 /*
   2  * Rayman 2 APM (De)muxer
   3  *
   4  * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "config_components.h"
  24
  25 #include "avformat.h"
  26 #include "avio_internal.h"
  27 #include "demux.h"
  28 #include "internal.h"
  29 #include "mux.h"
  30 #include "rawenc.h"
  31 #include "libavutil/channel_layout.h"
  32 #include "libavutil/internal.h"
  33 #include "libavutil/intreadwrite.h"
  34
  35 #define APM_FILE_HEADER_SIZE    20
  36 #define APM_FILE_EXTRADATA_SIZE 80
  37 #define APM_EXTRADATA_SIZE      28
  38
  39 #define APM_MAX_READ_SIZE       4096
  40
  41 #define APM_TAG_CODEC           0x2000
  42 #define APM_TAG_VS12            MKTAG('v', 's', '1', '2')
  43 #define APM_TAG_DATA            MKTAG('D', 'A', 'T', 'A')
  44
  45 typedef struct APMState {
  46     int32_t     has_saved;
  47     int32_t     predictor_r;
  48     int32_t     step_index_r;
  49     int32_t     saved_r;
  50     int32_t     predictor_l;
  51     int32_t     step_index_l;
  52     int32_t     saved_l;
  53 } APMState;
  54
  55 typedef struct APMExtraData {
  56     uint32_t    magic;
  57     uint32_t    file_size;
  58     uint32_t    data_size;
  59     uint32_t    unk1;
  60     uint32_t    unk2;
  61     APMState    state;
  62     uint32_t    unk3[7];
  63     uint32_t    data;
  64 } APMExtraData;
  65
  66 #if CONFIG_APM_DEMUXER
  67 static void apm_parse_extradata(APMExtraData *ext, const uint8_t *buf)
  68 {
  69     ext->magic              = AV_RL32(buf + 0);
  70     ext->file_size          = AV_RL32(buf + 4);
  71     ext->data_size          = AV_RL32(buf + 8);
  72     ext->unk1               = AV_RL32(buf + 12);
  73     ext->unk2               = AV_RL32(buf + 16);
  74
  75     ext->state.has_saved    = AV_RL32(buf + 20);
  76     ext->state.predictor_r  = AV_RL32(buf + 24);
  77     ext->state.step_index_r = AV_RL32(buf + 28);
  78     ext->state.saved_r      = AV_RL32(buf + 32);
  79     ext->state.predictor_l  = AV_RL32(buf + 36);
  80     ext->state.step_index_l = AV_RL32(buf + 40);
  81     ext->state.saved_l      = AV_RL32(buf + 44);
  82
  83     for (int i = 0; i < FF_ARRAY_ELEMS(ext->unk3); i++)
  84         ext->unk3[i]        = AV_RL32(buf + 48 + (i * 4));
  85
  86     ext->data               = AV_RL32(buf + 76);
  87 }
  88
  89 static int apm_probe(const AVProbeData *p)
  90 {
  91     if (AV_RL16(p->buf) != APM_TAG_CODEC)
  92         return 0;
  93
  94     if (p->buf_size < 100)
  95         return 0;
  96
  97     if (AV_RL32(p->buf + 20) != APM_TAG_VS12)
  98         return 0;
  99
 100     if (AV_RL32(p->buf + 96) != APM_TAG_DATA)
 101         return 0;
 102
 103     return AVPROBE_SCORE_MAX - 1;
 104 }
 105
 106 static int apm_read_header(AVFormatContext *s)
 107 {
 108     int64_t ret;
 109     AVStream *st;
 110     APMExtraData extradata;
 111     AVCodecParameters *par;
 112     uint8_t buf[APM_FILE_EXTRADATA_SIZE];
 113     int channels;
 114
 115     if (!(st = avformat_new_stream(s, NULL)))
 116         return AVERROR(ENOMEM);
 117
 118     /*
 119      * This is 98% a WAVEFORMATEX, but there's something screwy with the extradata
 120      * that ff_get_wav_header() can't (and shouldn't) handle properly.
 121      */
 122     if (avio_rl16(s->pb) != APM_TAG_CODEC)
 123         return AVERROR_INVALIDDATA;
 124
 125     par = st->codecpar;
 126     channels                   = avio_rl16(s->pb);
 127     par->sample_rate           = avio_rl32(s->pb);
 128
 129     /* Skip the bitrate, it's usually wrong anyway. */
 130     if ((ret = avio_skip(s->pb, 4)) < 0)
 131         return ret;
 132
 133     par->block_align           = avio_rl16(s->pb);
 134     par->bits_per_coded_sample = avio_rl16(s->pb);
 135
 136     if (avio_rl32(s->pb) != APM_FILE_EXTRADATA_SIZE)
 137         return AVERROR_INVALIDDATA;
 138
 139     /* 8 = bits per sample * max channels */
 140     if (par->sample_rate > (INT_MAX / 8))
 141         return AVERROR_INVALIDDATA;
 142
 143     if (par->bits_per_coded_sample != 4)
 144         return AVERROR_INVALIDDATA;
 145
 146     if (channels > 2 || channels == 0)
 147         return AVERROR_INVALIDDATA;
 148
 149     av_channel_layout_default(&par->ch_layout, channels);
 150     par->codec_type            = AVMEDIA_TYPE_AUDIO;
 151     par->codec_id              = AV_CODEC_ID_ADPCM_IMA_APM;
 152     par->format                = AV_SAMPLE_FMT_S16;
 153     par->bit_rate              = par->ch_layout.nb_channels *
 154                                  (int64_t)par->sample_rate *
 155                                  par->bits_per_coded_sample;
 156
 157     if ((ret = ffio_read_size(s->pb, buf, APM_FILE_EXTRADATA_SIZE)) < 0)
 158         return ret;
 159
 160     apm_parse_extradata(&extradata, buf);
 161
 162     if (extradata.magic != APM_TAG_VS12 || extradata.data != APM_TAG_DATA)
 163         return AVERROR_INVALIDDATA;
 164
 165     if (extradata.state.has_saved) {
 166         avpriv_request_sample(s, "Saved Samples");
 167         return AVERROR_PATCHWELCOME;
 168     }
 169
 170     if ((ret = ff_alloc_extradata(par, APM_EXTRADATA_SIZE)) < 0)
 171         return ret;
 172
 173     /* Use the entire state as extradata. */
 174     memcpy(par->extradata, buf + 20, APM_EXTRADATA_SIZE);
 175
 176     avpriv_set_pts_info(st, 64, 1, par->sample_rate);
 177     st->start_time  = 0;
 178     st->duration    = extradata.data_size *
 179                       (8 / par->bits_per_coded_sample) /
 180                       par->ch_layout.nb_channels;
 181     return 0;
 182 }
 183
 184 static int apm_read_packet(AVFormatContext *s, AVPacket *pkt)
 185 {
 186     int ret;
 187     AVCodecParameters *par = s->streams[0]->codecpar;
 188
 189     /*
 190      * For future reference: if files with the `has_saved` field set ever
 191      * surface, `saved_l`, and `saved_r` will each contain 8 "saved" samples
 192      * that should be sent to the decoder before the actual data.
 193      */
 194
 195     if ((ret = av_get_packet(s->pb, pkt, APM_MAX_READ_SIZE)) < 0)
 196         return ret;
 197
 198     pkt->flags          &= ~AV_PKT_FLAG_CORRUPT;
 199     pkt->stream_index   = 0;
 200     pkt->duration       = ret * (8 / par->bits_per_coded_sample) / par->ch_layout.nb_channels;
 201
 202     return 0;
 203 }
 204
 205 const FFInputFormat ff_apm_demuxer = {
 206     .p.name         = "apm",
 207     .p.long_name    = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
 208     .read_probe     = apm_probe,
 209     .read_header    = apm_read_header,
 210     .read_packet    = apm_read_packet
 211 };
 212 #endif
 213
 214 #if CONFIG_APM_MUXER
 215 static int apm_write_init(AVFormatContext *s)
 216 {
 217     AVCodecParameters *par = s->streams[0]->codecpar;
 218
 219     if (par->ch_layout.nb_channels > 2) {
 220         av_log(s, AV_LOG_ERROR, "APM files only support up to 2 channels\n");
 221         return AVERROR(EINVAL);
 222     }
 223
 224     if (par->sample_rate > (INT_MAX / 8)) {
 225         av_log(s, AV_LOG_ERROR, "Sample rate too large\n");
 226         return AVERROR(EINVAL);
 227     }
 228
 229     if (par->extradata_size != APM_EXTRADATA_SIZE) {
 230         av_log(s, AV_LOG_ERROR, "Invalid/missing extradata\n");
 231         return AVERROR(EINVAL);
 232     }
 233
 234     if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL)) {
 235         av_log(s, AV_LOG_ERROR, "Stream not seekable, unable to write output file\n");
 236         return AVERROR(EINVAL);
 237     }
 238
 239     return 0;
 240 }
 241
 242 static int apm_write_header(AVFormatContext *s)
 243 {
 244     uint8_t buf[APM_FILE_EXTRADATA_SIZE] = { 0 };
 245     AVCodecParameters *par = s->streams[0]->codecpar;
 246
 247     /*
 248      * Bodge a WAVEFORMATEX manually, ff_put_wav_header() can't
 249      * be used because of the extra 2 bytes.
 250      */
 251     avio_wl16(s->pb, APM_TAG_CODEC);
 252     avio_wl16(s->pb, par->ch_layout.nb_channels);
 253     avio_wl32(s->pb, par->sample_rate);
 254     /* This is the wrong calculation, but it's what the original files have. */
 255     avio_wl32(s->pb, par->sample_rate * par->ch_layout.nb_channels * 2);
 256     avio_wl16(s->pb, par->block_align);
 257     avio_wl16(s->pb, par->bits_per_coded_sample);
 258     avio_wl32(s->pb, APM_FILE_EXTRADATA_SIZE);
 259
 260     /*
 261      * Build the extradata. Assume the codec's given us correct data.
 262      * File and data sizes are fixed later.
 263      */
 264     AV_WL32(buf +  0, APM_TAG_VS12); /* magic */
 265     AV_WL32(buf + 12, 0xFFFFFFFF);   /* unk1  */
 266     memcpy( buf + 20, par->extradata, APM_EXTRADATA_SIZE);
 267     AV_WL32(buf + 76, APM_TAG_DATA); /* data */
 268
 269     avio_write(s->pb, buf, APM_FILE_EXTRADATA_SIZE);
 270     return 0;
 271 }
 272
 273 static int apm_write_trailer(AVFormatContext *s)
 274 {
 275     int64_t file_size, data_size;
 276
 277     file_size = avio_tell(s->pb);
 278     data_size = file_size - (APM_FILE_HEADER_SIZE + APM_FILE_EXTRADATA_SIZE);
 279
 280     if (file_size >= UINT32_MAX) {
 281         av_log(s, AV_LOG_ERROR,
 282                "Filesize %"PRId64" invalid for APM, output file will be broken\n",
 283                file_size);
 284         return AVERROR(ERANGE);
 285     }
 286
 287     avio_seek(s->pb, 24, SEEK_SET);
 288     avio_wl32(s->pb, (uint32_t)file_size);
 289     avio_wl32(s->pb, (uint32_t)data_size);
 290
 291     return 0;
 292 }
 293
 294 const FFOutputFormat ff_apm_muxer = {
 295     .p.name         = "apm",
 296     .p.long_name    = NULL_IF_CONFIG_SMALL("Ubisoft Rayman 2 APM"),
 297     .p.extensions   = "apm",
 298     .p.audio_codec  = AV_CODEC_ID_ADPCM_IMA_APM,
 299     .p.video_codec  = AV_CODEC_ID_NONE,
 300     .p.subtitle_codec = AV_CODEC_ID_NONE,
 301     .flags_internal   = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
 302                         FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
 303     .init           = apm_write_init,
 304     .write_header   = apm_write_header,
 305     .write_packet   = ff_raw_write_packet,
 306     .write_trailer  = apm_write_trailer
 307 };
 308 #endif