FFmpeg: libavformat/sierravmd.c Source File

00001 /*
00002  * Sierra VMD Format Demuxer
00003  * Copyright (c) 2004 The ffmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00030 #include "libavutil/intreadwrite.h"
00031 #include "avformat.h"
00032 
00033 #define VMD_HEADER_SIZE 0x0330
00034 #define BYTES_PER_FRAME_RECORD 16
00035 
00036 typedef struct {
00037   int stream_index;
00038   int64_t frame_offset;
00039   unsigned int frame_size;
00040   int64_t pts;
00041   int keyframe;
00042   unsigned char frame_record[BYTES_PER_FRAME_RECORD];
00043 } vmd_frame;
00044 
00045 typedef struct VmdDemuxContext {
00046     int video_stream_index;
00047     int audio_stream_index;
00048 
00049     unsigned int frame_count;
00050     unsigned int frames_per_block;
00051     vmd_frame *frame_table;
00052     unsigned int current_frame;
00053     int is_indeo3;
00054 
00055     int sample_rate;
00056     int64_t audio_sample_counter;
00057     int skiphdr;
00058 
00059     unsigned char vmd_header[VMD_HEADER_SIZE];
00060 } VmdDemuxContext;
00061 
00062 static int vmd_probe(AVProbeData *p)
00063 {
00064     /* check if the first 2 bytes of the file contain the appropriate size
00065      * of a VMD header chunk */
00066     if (AV_RL16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
00067         return 0;
00068 
00069     /* only return half certainty since this check is a bit sketchy */
00070     return AVPROBE_SCORE_MAX / 2;
00071 }
00072 
00073 static int vmd_read_header(AVFormatContext *s,
00074                            AVFormatParameters *ap)
00075 {
00076     VmdDemuxContext *vmd = s->priv_data;
00077     ByteIOContext *pb = s->pb;
00078     AVStream *st = NULL, *vst;
00079     unsigned int toc_offset;
00080     unsigned char *raw_frame_table;
00081     int raw_frame_table_size;
00082     int64_t current_offset;
00083     int i, j;
00084     unsigned int total_frames;
00085     int64_t current_audio_pts = 0;
00086     unsigned char chunk[BYTES_PER_FRAME_RECORD];
00087     int num, den;
00088     int sound_buffers;
00089 
00090     /* fetch the main header, including the 2 header length bytes */
00091     url_fseek(pb, 0, SEEK_SET);
00092     if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
00093         return AVERROR(EIO);
00094 
00095     if(vmd->vmd_header[16] == 'i' && vmd->vmd_header[17] == 'v' && vmd->vmd_header[18] == '3')
00096         vmd->is_indeo3 = 1;
00097     else
00098         vmd->is_indeo3 = 0;
00099     /* start up the decoders */
00100     vst = av_new_stream(s, 0);
00101     if (!vst)
00102         return AVERROR(ENOMEM);
00103     av_set_pts_info(vst, 33, 1, 10);
00104     vmd->video_stream_index = vst->index;
00105     vst->codec->codec_type = CODEC_TYPE_VIDEO;
00106     vst->codec->codec_id = vmd->is_indeo3 ? CODEC_ID_INDEO3 : CODEC_ID_VMDVIDEO;
00107     vst->codec->codec_tag = 0;  /* no fourcc */
00108     vst->codec->width = AV_RL16(&vmd->vmd_header[12]);
00109     vst->codec->height = AV_RL16(&vmd->vmd_header[14]);
00110     if(vmd->is_indeo3 && vst->codec->width > 320){
00111         vst->codec->width >>= 1;
00112         vst->codec->height >>= 1;
00113     }
00114     vst->codec->extradata_size = VMD_HEADER_SIZE;
00115     vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
00116     memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
00117 
00118     /* if sample rate is 0, assume no audio */
00119     vmd->sample_rate = AV_RL16(&vmd->vmd_header[804]);
00120     if (vmd->sample_rate) {
00121         st = av_new_stream(s, 0);
00122         if (!st)
00123             return AVERROR(ENOMEM);
00124         vmd->audio_stream_index = st->index;
00125         st->codec->codec_type = CODEC_TYPE_AUDIO;
00126         st->codec->codec_id = CODEC_ID_VMDAUDIO;
00127         st->codec->codec_tag = 0;  /* no fourcc */
00128         st->codec->channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
00129         st->codec->sample_rate = vmd->sample_rate;
00130         st->codec->block_align = AV_RL16(&vmd->vmd_header[806]);
00131         if (st->codec->block_align & 0x8000) {
00132             st->codec->bits_per_coded_sample = 16;
00133             st->codec->block_align = -(st->codec->block_align - 0x10000);
00134         } else {
00135             st->codec->bits_per_coded_sample = 8;
00136         }
00137         st->codec->bit_rate = st->codec->sample_rate *
00138             st->codec->bits_per_coded_sample * st->codec->channels;
00139 
00140         /* calculate pts */
00141         num = st->codec->block_align;
00142         den = st->codec->sample_rate * st->codec->channels;
00143         av_reduce(&den, &num, den, num, (1UL<<31)-1);
00144         av_set_pts_info(vst, 33, num, den);
00145         av_set_pts_info(st, 33, num, den);
00146     }
00147 
00148     toc_offset = AV_RL32(&vmd->vmd_header[812]);
00149     vmd->frame_count = AV_RL16(&vmd->vmd_header[6]);
00150     vmd->frames_per_block = AV_RL16(&vmd->vmd_header[18]);
00151     url_fseek(pb, toc_offset, SEEK_SET);
00152 
00153     raw_frame_table = NULL;
00154     vmd->frame_table = NULL;
00155     sound_buffers = AV_RL16(&vmd->vmd_header[808]);
00156     raw_frame_table_size = vmd->frame_count * 6;
00157     if(vmd->frame_count * vmd->frames_per_block  >= UINT_MAX / sizeof(vmd_frame)){
00158         av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
00159         return -1;
00160     }
00161     raw_frame_table = av_malloc(raw_frame_table_size);
00162     vmd->frame_table = av_malloc((vmd->frame_count * vmd->frames_per_block + sound_buffers) * sizeof(vmd_frame));
00163     if (!raw_frame_table || !vmd->frame_table) {
00164         av_free(raw_frame_table);
00165         av_free(vmd->frame_table);
00166         return AVERROR(ENOMEM);
00167     }
00168     if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
00169         raw_frame_table_size) {
00170         av_free(raw_frame_table);
00171         av_free(vmd->frame_table);
00172         return AVERROR(EIO);
00173     }
00174 
00175     total_frames = 0;
00176     for (i = 0; i < vmd->frame_count; i++) {
00177 
00178         current_offset = AV_RL32(&raw_frame_table[6 * i + 2]);
00179 
00180         /* handle each entry in index block */
00181         for (j = 0; j < vmd->frames_per_block; j++) {
00182             int type;
00183             uint32_t size;
00184 
00185             get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
00186             type = chunk[0];
00187             size = AV_RL32(&chunk[2]);
00188             if(!size && type != 1)
00189                 continue;
00190             switch(type) {
00191             case 1: /* Audio Chunk */
00192                 if (!st) break;
00193                 /* first audio chunk contains several audio buffers */
00194                 vmd->frame_table[total_frames].frame_offset = current_offset;
00195                 vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
00196                 vmd->frame_table[total_frames].frame_size = size;
00197                 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
00198                 vmd->frame_table[total_frames].pts = current_audio_pts;
00199                 total_frames++;
00200                 if(!current_audio_pts)
00201                     current_audio_pts += sound_buffers;
00202                 else
00203                     current_audio_pts++;
00204                 break;
00205             case 2: /* Video Chunk */
00206                 vmd->frame_table[total_frames].frame_offset = current_offset;
00207                 vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
00208                 vmd->frame_table[total_frames].frame_size = size;
00209                 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
00210                 vmd->frame_table[total_frames].pts = i;
00211                 total_frames++;
00212                 break;
00213             }
00214             current_offset += size;
00215         }
00216     }
00217 
00218     av_free(raw_frame_table);
00219 
00220     vmd->current_frame = 0;
00221     vmd->frame_count = total_frames;
00222 
00223     return 0;
00224 }
00225 
00226 static int vmd_read_packet(AVFormatContext *s,
00227                            AVPacket *pkt)
00228 {
00229     VmdDemuxContext *vmd = s->priv_data;
00230     ByteIOContext *pb = s->pb;
00231     int ret = 0;
00232     vmd_frame *frame;
00233 
00234     if (vmd->current_frame >= vmd->frame_count)
00235         return AVERROR(EIO);
00236 
00237     frame = &vmd->frame_table[vmd->current_frame];
00238     /* position the stream (will probably be there already) */
00239     url_fseek(pb, frame->frame_offset, SEEK_SET);
00240 
00241     if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
00242         return AVERROR(ENOMEM);
00243     pkt->pos= url_ftell(pb);
00244     memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
00245     if(vmd->is_indeo3)
00246         ret = get_buffer(pb, pkt->data, frame->frame_size);
00247     else
00248         ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
00249             frame->frame_size);
00250 
00251     if (ret != frame->frame_size) {
00252         av_free_packet(pkt);
00253         ret = AVERROR(EIO);
00254     }
00255     pkt->stream_index = frame->stream_index;
00256     pkt->pts = frame->pts;
00257     av_log(s, AV_LOG_DEBUG, " dispatching %s frame with %d bytes and pts %"PRId64"\n",
00258             (frame->frame_record[0] == 0x02) ? "video" : "audio",
00259             frame->frame_size + BYTES_PER_FRAME_RECORD,
00260             pkt->pts);
00261 
00262     vmd->current_frame++;
00263 
00264     return ret;
00265 }
00266 
00267 static int vmd_read_close(AVFormatContext *s)
00268 {
00269     VmdDemuxContext *vmd = s->priv_data;
00270 
00271     av_free(vmd->frame_table);
00272 
00273     return 0;
00274 }
00275 
00276 AVInputFormat vmd_demuxer = {
00277     "vmd",
00278     NULL_IF_CONFIG_SMALL("Sierra VMD format"),
00279     sizeof(VmdDemuxContext),
00280     vmd_probe,
00281     vmd_read_header,
00282     vmd_read_packet,
00283     vmd_read_close,
00284 };