libavformat/idcin.c

   1 /*
   2  * id Quake II CIN File Demuxer
   3  * Copyright (c) 2003 The FFmpeg project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * id Quake II CIN file demuxer by Mike Melanson (melanson@pcisys.net)
  25  * For more information about the id CIN format, visit:
  26  *   http://www.csse.monash.edu.au/~timf/
  27  *
  28  * CIN is a somewhat quirky and ill-defined format. Here are some notes
  29  * for anyone trying to understand the technical details of this format:
  30  *
  31  * The format has no definite file signature. This is problematic for a
  32  * general-purpose media player that wants to automatically detect file
  33  * types. However, a CIN file does start with 5 32-bit numbers that
  34  * specify audio and video parameters. This demuxer gets around the lack
  35  * of file signature by performing sanity checks on those parameters.
  36  * Probabilistically, this is a reasonable solution since the number of
  37  * valid combinations of the 5 parameters is a very small subset of the
  38  * total 160-bit number space.
  39  *
  40  * Refer to the function idcin_probe() for the precise A/V parameters
  41  * that this demuxer allows.
  42  *
  43  * Next, each audio and video frame has a duration of 1/14 sec. If the
  44  * audio sample rate is a multiple of the common frequency 22050 Hz it will
  45  * divide evenly by 14. However, if the sample rate is 11025 Hz:
  46  *   11025 (samples/sec) / 14 (frames/sec) = 787.5 (samples/frame)
  47  * The way the CIN stores audio in this case is by storing 787 sample
  48  * frames in the first audio frame and 788 sample frames in the second
  49  * audio frame. Therefore, the total number of bytes in an audio frame
  50  * is given as:
  51  *   audio frame #0: 787 * (bytes/sample) * (# channels) bytes in frame
  52  *   audio frame #1: 788 * (bytes/sample) * (# channels) bytes in frame
  53  *   audio frame #2: 787 * (bytes/sample) * (# channels) bytes in frame
  54  *   audio frame #3: 788 * (bytes/sample) * (# channels) bytes in frame
  55  *
  56  * Finally, not all id CIN creation tools agree on the resolution of the
  57  * color palette, apparently. Some creation tools specify red, green, and
  58  * blue palette components in terms of 6-bit VGA color DAC values which
  59  * range from 0..63. Other tools specify the RGB components as full 8-bit
  60  * values that range from 0..255. Since there are no markers in the file to
  61  * differentiate between the two variants, this demuxer uses the following
  62  * heuristic:
  63  *   - load the 768 palette bytes from disk
  64  *   - assume that they will need to be shifted left by 2 bits to
  65  *     transform them from 6-bit values to 8-bit values
  66  *   - scan through all 768 palette bytes
  67  *     - if any bytes exceed 63, do not shift the bytes at all before
  68  *       transmitting them to the video decoder
  69  */
  70
  71 #include "libavutil/channel_layout.h"
  72 #include "libavutil/imgutils.h"
  73 #include "libavutil/intreadwrite.h"
  74 #include "avformat.h"
  75 #include "demux.h"
  76 #include "internal.h"
  77
  78 #define HUFFMAN_TABLE_SIZE (64 * 1024)
  79 #define IDCIN_FPS 14
  80
  81 typedef struct IdcinDemuxContext {
  82     int video_stream_index;
  83     int audio_stream_index;
  84     int audio_chunk_size1;
  85     int audio_chunk_size2;
  86     int block_align;
  87
  88     /* demux state variables */
  89     int current_audio_chunk;
  90     int next_chunk_is_video;
  91     int audio_present;
  92     int64_t first_pkt_pos;
  93 } IdcinDemuxContext;
  94
  95 static int idcin_probe(const AVProbeData *p)
  96 {
  97     unsigned int number, sample_rate;
  98     unsigned int w, h;
  99     int i;
 100
 101     /*
 102      * This is what you could call a "probabilistic" file check: id CIN
 103      * files don't have a definite file signature. In lieu of such a marker,
 104      * perform sanity checks on the 5 32-bit header fields:
 105      *  width, height: greater than 0, less than or equal to 1024
 106      * audio sample rate: greater than or equal to 8000, less than or
 107      *  equal to 48000, or 0 for no audio
 108      * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
 109      * audio channels: 0 for no audio, or 1 or 2
 110      */
 111
 112     /* check we have enough data to do all checks, otherwise the
 113        0-padding may cause a wrong recognition */
 114     if (p->buf_size < 20 + HUFFMAN_TABLE_SIZE + 12)
 115         return 0;
 116
 117     /* check the video width */
 118     w = AV_RL32(&p->buf[0]);
 119     if ((w == 0) || (w > 1024))
 120        return 0;
 121
 122     /* check the video height */
 123     h = AV_RL32(&p->buf[4]);
 124     if ((h == 0) || (h > 1024))
 125        return 0;
 126
 127     /* check the audio sample rate */
 128     sample_rate = AV_RL32(&p->buf[8]);
 129     if (sample_rate && (sample_rate < 8000 || sample_rate > 48000))
 130         return 0;
 131
 132     /* check the audio bytes/sample */
 133     number = AV_RL32(&p->buf[12]);
 134     if (number > 2 || sample_rate && !number)
 135         return 0;
 136
 137     /* check the audio channels */
 138     number = AV_RL32(&p->buf[16]);
 139     if (number > 2 || sample_rate && !number)
 140         return 0;
 141
 142     i = 20 + HUFFMAN_TABLE_SIZE;
 143     if (AV_RL32(&p->buf[i]) == 1)
 144         i += 768;
 145
 146     if (i+12 > p->buf_size || AV_RL32(&p->buf[i+8]) != w*h)
 147         return 1;
 148
 149     /* return half certainty since this check is a bit sketchy */
 150     return AVPROBE_SCORE_EXTENSION;
 151 }
 152
 153 static int idcin_read_header(AVFormatContext *s)
 154 {
 155     AVIOContext *pb = s->pb;
 156     IdcinDemuxContext *idcin = s->priv_data;
 157     AVStream *st;
 158     unsigned int width, height;
 159     unsigned int sample_rate, bytes_per_sample, channels;
 160     int ret;
 161
 162     /* get the 5 header parameters */
 163     width = avio_rl32(pb);
 164     height = avio_rl32(pb);
 165     sample_rate = avio_rl32(pb);
 166     bytes_per_sample = avio_rl32(pb);
 167     channels = avio_rl32(pb);
 168
 169     if (s->pb->eof_reached) {
 170         av_log(s, AV_LOG_ERROR, "incomplete header\n");
 171         return s->pb->error ? s->pb->error : AVERROR_EOF;
 172     }
 173
 174     if (av_image_check_size(width, height, 0, s) < 0)
 175         return AVERROR_INVALIDDATA;
 176     if (sample_rate > 0) {
 177         if (sample_rate < 14 || sample_rate > INT_MAX) {
 178             av_log(s, AV_LOG_ERROR, "invalid sample rate: %u\n", sample_rate);
 179             return AVERROR_INVALIDDATA;
 180         }
 181         if (bytes_per_sample < 1 || bytes_per_sample > 2) {
 182             av_log(s, AV_LOG_ERROR, "invalid bytes per sample: %u\n",
 183                    bytes_per_sample);
 184             return AVERROR_INVALIDDATA;
 185         }
 186         if (channels < 1 || channels > 2) {
 187             av_log(s, AV_LOG_ERROR, "invalid channels: %u\n", channels);
 188             return AVERROR_INVALIDDATA;
 189         }
 190         idcin->audio_present = 1;
 191     } else {
 192         /* if sample rate is 0, assume no audio */
 193         idcin->audio_present = 0;
 194     }
 195
 196     st = avformat_new_stream(s, NULL);
 197     if (!st)
 198         return AVERROR(ENOMEM);
 199     avpriv_set_pts_info(st, 33, 1, IDCIN_FPS);
 200     st->start_time = 0;
 201     idcin->video_stream_index = st->index;
 202     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 203     st->codecpar->codec_id = AV_CODEC_ID_IDCIN;
 204     st->codecpar->codec_tag = 0;  /* no fourcc */
 205     st->codecpar->width = width;
 206     st->codecpar->height = height;
 207
 208     /* load up the Huffman tables into extradata */
 209     if ((ret = ff_get_extradata(s, st->codecpar, pb, HUFFMAN_TABLE_SIZE)) < 0)
 210         return ret;
 211
 212     if (idcin->audio_present) {
 213         idcin->audio_present = 1;
 214         st = avformat_new_stream(s, NULL);
 215         if (!st)
 216             return AVERROR(ENOMEM);
 217         avpriv_set_pts_info(st, 63, 1, sample_rate);
 218         st->start_time = 0;
 219         idcin->audio_stream_index = st->index;
 220         st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 221         st->codecpar->codec_tag = 1;
 222         av_channel_layout_default(&st->codecpar->ch_layout, channels);
 223         st->codecpar->sample_rate = sample_rate;
 224         st->codecpar->bits_per_coded_sample = bytes_per_sample * 8;
 225         st->codecpar->bit_rate = sample_rate * bytes_per_sample * 8 * channels;
 226         st->codecpar->block_align = idcin->block_align = bytes_per_sample * channels;
 227         if (bytes_per_sample == 1)
 228             st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
 229         else
 230             st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
 231
 232         if (sample_rate % 14 != 0) {
 233             idcin->audio_chunk_size1 = (sample_rate / 14) *
 234             bytes_per_sample * channels;
 235             idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
 236                 bytes_per_sample * channels;
 237         } else {
 238             idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
 239                 (sample_rate / 14) * bytes_per_sample * channels;
 240         }
 241         idcin->current_audio_chunk = 0;
 242     }
 243
 244     idcin->next_chunk_is_video = 1;
 245     idcin->first_pkt_pos = avio_tell(s->pb);
 246
 247     return 0;
 248 }
 249
 250 static int idcin_read_packet(AVFormatContext *s,
 251                              AVPacket *pkt)
 252 {
 253     int ret;
 254     unsigned int command;
 255     unsigned int chunk_size;
 256     IdcinDemuxContext *idcin = s->priv_data;
 257     AVIOContext *pb = s->pb;
 258     int i;
 259     int palette_scale;
 260     unsigned char r, g, b;
 261     unsigned char palette_buffer[768];
 262     uint32_t palette[256];
 263
 264     if (avio_feof(s->pb))
 265         return s->pb->error ? s->pb->error : AVERROR_EOF;
 266
 267     if (idcin->next_chunk_is_video) {
 268         command = avio_rl32(pb);
 269         if (command == 2) {
 270             return AVERROR_INVALIDDATA;
 271         } else if (command == 1) {
 272             /* trigger a palette change */
 273             ret = avio_read(pb, palette_buffer, 768);
 274             if (ret < 0) {
 275                 return ret;
 276             } else if (ret != 768) {
 277                 av_log(s, AV_LOG_ERROR, "incomplete packet\n");
 278                 return AVERROR_INVALIDDATA;
 279             }
 280             /* scale the palette as necessary */
 281             palette_scale = 2;
 282             for (i = 0; i < 768; i++)
 283                 if (palette_buffer[i] > 63) {
 284                     palette_scale = 0;
 285                     break;
 286                 }
 287
 288             for (i = 0; i < 256; i++) {
 289                 r = palette_buffer[i * 3    ] << palette_scale;
 290                 g = palette_buffer[i * 3 + 1] << palette_scale;
 291                 b = palette_buffer[i * 3 + 2] << palette_scale;
 292                 palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
 293                 if (palette_scale == 2)
 294                     palette[i] |= palette[i] >> 6 & 0x30303;
 295             }
 296         }
 297
 298         if (s->pb->eof_reached) {
 299             av_log(s, AV_LOG_ERROR, "incomplete packet\n");
 300             return s->pb->error ? s->pb->error : AVERROR_EOF;
 301         }
 302         chunk_size = avio_rl32(pb);
 303         if (chunk_size < 4 || chunk_size > INT_MAX - 4) {
 304             av_log(s, AV_LOG_ERROR, "invalid chunk size: %u\n", chunk_size);
 305             return AVERROR_INVALIDDATA;
 306         }
 307         /* skip the number of decoded bytes (always equal to width * height) */
 308         avio_skip(pb, 4);
 309         chunk_size -= 4;
 310         ret= av_get_packet(pb, pkt, chunk_size);
 311         if (ret < 0)
 312             return ret;
 313         else if (ret != chunk_size) {
 314             av_log(s, AV_LOG_ERROR, "incomplete packet\n");
 315             return AVERROR_INVALIDDATA;
 316         }
 317         if (command == 1) {
 318             uint8_t *pal;
 319
 320             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
 321                                           AVPALETTE_SIZE);
 322             if (!pal) {
 323                 return AVERROR(ENOMEM);
 324             }
 325             memcpy(pal, palette, AVPALETTE_SIZE);
 326             pkt->flags |= AV_PKT_FLAG_KEY;
 327         }
 328         pkt->stream_index = idcin->video_stream_index;
 329         pkt->duration     = 1;
 330     } else {
 331         /* send out the audio chunk */
 332         if (idcin->current_audio_chunk)
 333             chunk_size = idcin->audio_chunk_size2;
 334         else
 335             chunk_size = idcin->audio_chunk_size1;
 336         ret= av_get_packet(pb, pkt, chunk_size);
 337         if (ret < 0)
 338             return ret;
 339         pkt->stream_index = idcin->audio_stream_index;
 340         pkt->duration     = chunk_size / idcin->block_align;
 341
 342         idcin->current_audio_chunk ^= 1;
 343     }
 344
 345     if (idcin->audio_present)
 346         idcin->next_chunk_is_video ^= 1;
 347
 348     return 0;
 349 }
 350
 351 static int idcin_read_seek(AVFormatContext *s, int stream_index,
 352                            int64_t timestamp, int flags)
 353 {
 354     IdcinDemuxContext *idcin = s->priv_data;
 355
 356     if (idcin->first_pkt_pos > 0) {
 357         int64_t ret = avio_seek(s->pb, idcin->first_pkt_pos, SEEK_SET);
 358         if (ret < 0)
 359             return ret;
 360         avpriv_update_cur_dts(s, s->streams[idcin->video_stream_index], 0);
 361         idcin->next_chunk_is_video = 1;
 362         idcin->current_audio_chunk = 0;
 363         return 0;
 364     }
 365     return -1;
 366 }
 367
 368 const FFInputFormat ff_idcin_demuxer = {
 369     .p.name         = "idcin",
 370     .p.long_name    = NULL_IF_CONFIG_SMALL("id Cinematic"),
 371     .p.flags        = AVFMT_NO_BYTE_SEEK,
 372     .priv_data_size = sizeof(IdcinDemuxContext),
 373     .read_probe     = idcin_probe,
 374     .read_header    = idcin_read_header,
 375     .read_packet    = idcin_read_packet,
 376     .read_seek      = idcin_read_seek,
 377 };