libavformat/rl2.c

   1 /*
   2  * RL2 Format Demuxer
   3  * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
   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  * RL2 file demuxer
  24  * @file
  25  * @author Sascha Sommer (saschasommer@freenet.de)
  26  * @see http://wiki.multimedia.cx/index.php?title=RL2
  27  *
  28  * extradata:
  29  * 2 byte le initial drawing offset within 320x200 viewport
  30  * 4 byte le number of used colors
  31  * 256 * 3 bytes rgb palette
  32  * optional background_frame
  33  */
  34
  35 #include <stdint.h>
  36
  37 #include "libavutil/intreadwrite.h"
  38 #include "libavutil/mathematics.h"
  39 #include "libavutil/mem.h"
  40 #include "avformat.h"
  41 #include "demux.h"
  42 #include "internal.h"
  43
  44 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
  45
  46 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
  47 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
  48 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
  49
  50 typedef struct Rl2DemuxContext {
  51     unsigned int index_pos[2];   ///< indexes in the sample tables
  52 } Rl2DemuxContext;
  53
  54
  55 /**
  56  * check if the file is in rl2 format
  57  * @param p probe buffer
  58  * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
  59  */
  60 static int rl2_probe(const AVProbeData *p)
  61 {
  62
  63     if(AV_RB32(&p->buf[0]) != FORM_TAG)
  64         return 0;
  65
  66     if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
  67         AV_RB32(&p->buf[8]) != RLV3_TAG)
  68         return 0;
  69
  70     return AVPROBE_SCORE_MAX;
  71 }
  72
  73 /**
  74  * read rl2 header data and setup the avstreams
  75  * @param s demuxer context
  76  * @return 0 on success, AVERROR otherwise
  77  */
  78 static av_cold int rl2_read_header(AVFormatContext *s)
  79 {
  80     AVIOContext *pb = s->pb;
  81     AVStream *st;
  82     unsigned int frame_count;
  83     unsigned int audio_frame_counter = 0;
  84     unsigned int video_frame_counter = 0;
  85     unsigned int back_size;
  86     unsigned short sound_rate;
  87     unsigned short rate;
  88     unsigned short channels;
  89     unsigned short def_sound_size;
  90     unsigned int signature;
  91     unsigned int pts_den = 11025; /* video only case */
  92     unsigned int pts_num = 1103;
  93     unsigned int* chunk_offset = NULL;
  94     int* chunk_size = NULL;
  95     int* audio_size = NULL;
  96     int i;
  97     int ret = 0;
  98
  99     avio_skip(pb,4);          /* skip FORM tag */
 100     back_size = avio_rl32(pb); /**< get size of the background frame */
 101     signature = avio_rb32(pb);
 102     avio_skip(pb, 4);         /* data size */
 103     frame_count = avio_rl32(pb);
 104
 105     /* disallow back_sizes and frame_counts that may lead to overflows later */
 106     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
 107         return AVERROR_INVALIDDATA;
 108
 109     avio_skip(pb, 2);         /* encoding method */
 110     sound_rate = avio_rl16(pb);
 111     rate = avio_rl16(pb);
 112     channels = avio_rl16(pb);
 113     def_sound_size = avio_rl16(pb);
 114
 115     /** setup video stream */
 116     st = avformat_new_stream(s, NULL);
 117     if(!st)
 118          return AVERROR(ENOMEM);
 119
 120     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 121     st->codecpar->codec_id = AV_CODEC_ID_RL2;
 122     st->codecpar->codec_tag = 0;  /* no fourcc */
 123     st->codecpar->width = 320;
 124     st->codecpar->height = 200;
 125
 126     /** allocate and fill extradata */
 127     st->codecpar->extradata_size = EXTRADATA1_SIZE;
 128
 129     if(signature == RLV3_TAG && back_size > 0)
 130         st->codecpar->extradata_size += back_size;
 131
 132     ret = ff_get_extradata(s, st->codecpar, pb, st->codecpar->extradata_size);
 133     if (ret < 0)
 134         return ret;
 135
 136     /** setup audio stream if present */
 137     if(sound_rate){
 138         if (!channels || channels > 42) {
 139             av_log(s, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);
 140             return AVERROR_INVALIDDATA;
 141         }
 142
 143         pts_num = def_sound_size;
 144         pts_den = rate;
 145
 146         st = avformat_new_stream(s, NULL);
 147         if (!st)
 148             return AVERROR(ENOMEM);
 149         st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 150         st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
 151         st->codecpar->codec_tag = 1;
 152         st->codecpar->ch_layout.nb_channels = channels;
 153         st->codecpar->bits_per_coded_sample = 8;
 154         st->codecpar->sample_rate = rate;
 155         st->codecpar->bit_rate = channels * st->codecpar->sample_rate *
 156             st->codecpar->bits_per_coded_sample;
 157         st->codecpar->block_align = channels *
 158             st->codecpar->bits_per_coded_sample / 8;
 159         avpriv_set_pts_info(st,32,1,rate);
 160     }
 161
 162     avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
 163
 164     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
 165     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
 166     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
 167
 168     if(!chunk_size || !audio_size || !chunk_offset){
 169         av_free(chunk_size);
 170         av_free(audio_size);
 171         av_free(chunk_offset);
 172         return AVERROR(ENOMEM);
 173     }
 174
 175     /** read offset and size tables */
 176     for(i=0; i < frame_count;i++) {
 177         if (avio_feof(pb)) {
 178             ret = AVERROR_INVALIDDATA;
 179             goto end;
 180         }
 181         chunk_size[i] = avio_rl32(pb);
 182     }
 183     for(i=0; i < frame_count;i++) {
 184         if (avio_feof(pb)) {
 185             ret = AVERROR_INVALIDDATA;
 186             goto end;
 187         }
 188         chunk_offset[i] = avio_rl32(pb);
 189     }
 190     for(i=0; i < frame_count;i++) {
 191         if (avio_feof(pb)) {
 192             ret = AVERROR_INVALIDDATA;
 193             goto end;
 194         }
 195         audio_size[i] = avio_rl32(pb) & 0xFFFF;
 196     }
 197
 198     /** build the sample index */
 199     for(i=0;i<frame_count;i++){
 200         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
 201             ret = AVERROR_INVALIDDATA;
 202             break;
 203         }
 204
 205         if(sound_rate && audio_size[i]){
 206             av_add_index_entry(s->streams[1], chunk_offset[i],
 207                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
 208             audio_frame_counter += audio_size[i] / channels;
 209         }
 210         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
 211             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
 212         ++video_frame_counter;
 213     }
 214
 215 end:
 216     av_free(chunk_size);
 217     av_free(audio_size);
 218     av_free(chunk_offset);
 219
 220     return ret;
 221 }
 222
 223 /**
 224  * read a single audio or video packet
 225  * @param s demuxer context
 226  * @param pkt the packet to be filled
 227  * @return 0 on success, AVERROR otherwise
 228  */
 229 static int rl2_read_packet(AVFormatContext *s,
 230                             AVPacket *pkt)
 231 {
 232     Rl2DemuxContext *rl2 = s->priv_data;
 233     AVIOContext *pb = s->pb;
 234     AVIndexEntry *sample = NULL;
 235     int i;
 236     int ret = 0;
 237     int stream_id = -1;
 238     int64_t pos = INT64_MAX;
 239
 240     /** check if there is a valid video or audio entry that can be used */
 241     for(i=0; i<s->nb_streams; i++){
 242         const FFStream *const sti = ffstream(s->streams[i]);
 243         if (rl2->index_pos[i] < sti->nb_index_entries
 244               && sti->index_entries[ rl2->index_pos[i] ].pos < pos) {
 245             sample = &sti->index_entries[ rl2->index_pos[i] ];
 246             pos= sample->pos;
 247             stream_id= i;
 248         }
 249     }
 250
 251     if(stream_id == -1)
 252         return AVERROR_EOF;
 253
 254     ++rl2->index_pos[stream_id];
 255
 256     /** position the stream (will probably be there anyway) */
 257     avio_seek(pb, sample->pos, SEEK_SET);
 258
 259     /** fill the packet */
 260     ret = av_get_packet(pb, pkt, sample->size);
 261     if(ret != sample->size){
 262         return AVERROR_INVALIDDATA;
 263     }
 264
 265     pkt->stream_index = stream_id;
 266     pkt->pts = sample->timestamp;
 267
 268     return ret;
 269 }
 270
 271 /**
 272  * seek to a new timestamp
 273  * @param s demuxer context
 274  * @param stream_index index of the stream that should be seeked
 275  * @param timestamp wanted timestamp
 276  * @param flags direction and seeking mode
 277  * @return 0 on success, -1 otherwise
 278  */
 279 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 280 {
 281     AVStream *st = s->streams[stream_index];
 282     Rl2DemuxContext *rl2 = s->priv_data;
 283     int i;
 284     int index = av_index_search_timestamp(st, timestamp, flags);
 285     if(index < 0)
 286         return -1;
 287
 288     rl2->index_pos[stream_index] = index;
 289     timestamp = ffstream(st)->index_entries[index].timestamp;
 290
 291     for(i=0; i < s->nb_streams; i++){
 292         AVStream *st2 = s->streams[i];
 293         index = av_index_search_timestamp(st2,
 294                     av_rescale_q(timestamp, st->time_base, st2->time_base),
 295                     flags | AVSEEK_FLAG_BACKWARD);
 296
 297         if(index < 0)
 298             index = 0;
 299
 300         rl2->index_pos[i] = index;
 301     }
 302
 303     return 0;
 304 }
 305
 306 const FFInputFormat ff_rl2_demuxer = {
 307     .p.name         = "rl2",
 308     .p.long_name    = NULL_IF_CONFIG_SMALL("RL2"),
 309     .priv_data_size = sizeof(Rl2DemuxContext),
 310     .read_probe     = rl2_probe,
 311     .read_header    = rl2_read_header,
 312     .read_packet    = rl2_read_packet,
 313     .read_seek      = rl2_read_seek,
 314 };