Libav
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00001 /* 00002 * "Real" compatible muxer. 00003 * Copyright (c) 2000, 2001 Fabrice Bellard 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 #include "avformat.h" 00022 #include "rm.h" 00023 00024 typedef struct { 00025 int nb_packets; 00026 int packet_total_size; 00027 int packet_max_size; 00028 /* codec related output */ 00029 int bit_rate; 00030 float frame_rate; 00031 int nb_frames; /* current frame number */ 00032 int total_frames; /* total number of frames */ 00033 int num; 00034 AVCodecContext *enc; 00035 } StreamInfo; 00036 00037 typedef struct { 00038 StreamInfo streams[2]; 00039 StreamInfo *audio_stream, *video_stream; 00040 int data_pos; /* position of the data after the header */ 00041 } RMMuxContext; 00042 00043 /* in ms */ 00044 #define BUFFER_DURATION 0 00045 00046 00047 static void put_str(ByteIOContext *s, const char *tag) 00048 { 00049 put_be16(s,strlen(tag)); 00050 while (*tag) { 00051 put_byte(s, *tag++); 00052 } 00053 } 00054 00055 static void put_str8(ByteIOContext *s, const char *tag) 00056 { 00057 put_byte(s, strlen(tag)); 00058 while (*tag) { 00059 put_byte(s, *tag++); 00060 } 00061 } 00062 00063 static void rv10_write_header(AVFormatContext *ctx, 00064 int data_size, int index_pos) 00065 { 00066 RMMuxContext *rm = ctx->priv_data; 00067 ByteIOContext *s = ctx->pb; 00068 StreamInfo *stream; 00069 unsigned char *data_offset_ptr, *start_ptr; 00070 const char *desc, *mimetype; 00071 int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i; 00072 int bit_rate, v, duration, flags, data_pos; 00073 AVMetadataTag *tag; 00074 00075 start_ptr = s->buf_ptr; 00076 00077 put_tag(s, ".RMF"); 00078 put_be32(s,18); /* header size */ 00079 put_be16(s,0); 00080 put_be32(s,0); 00081 put_be32(s,4 + ctx->nb_streams); /* num headers */ 00082 00083 put_tag(s,"PROP"); 00084 put_be32(s, 50); 00085 put_be16(s, 0); 00086 packet_max_size = 0; 00087 packet_total_size = 0; 00088 nb_packets = 0; 00089 bit_rate = 0; 00090 duration = 0; 00091 for(i=0;i<ctx->nb_streams;i++) { 00092 StreamInfo *stream = &rm->streams[i]; 00093 bit_rate += stream->bit_rate; 00094 if (stream->packet_max_size > packet_max_size) 00095 packet_max_size = stream->packet_max_size; 00096 nb_packets += stream->nb_packets; 00097 packet_total_size += stream->packet_total_size; 00098 /* select maximum duration */ 00099 v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate); 00100 if (v > duration) 00101 duration = v; 00102 } 00103 put_be32(s, bit_rate); /* max bit rate */ 00104 put_be32(s, bit_rate); /* avg bit rate */ 00105 put_be32(s, packet_max_size); /* max packet size */ 00106 if (nb_packets > 0) 00107 packet_avg_size = packet_total_size / nb_packets; 00108 else 00109 packet_avg_size = 0; 00110 put_be32(s, packet_avg_size); /* avg packet size */ 00111 put_be32(s, nb_packets); /* num packets */ 00112 put_be32(s, duration); /* duration */ 00113 put_be32(s, BUFFER_DURATION); /* preroll */ 00114 put_be32(s, index_pos); /* index offset */ 00115 /* computation of data the data offset */ 00116 data_offset_ptr = s->buf_ptr; 00117 put_be32(s, 0); /* data offset : will be patched after */ 00118 put_be16(s, ctx->nb_streams); /* num streams */ 00119 flags = 1 | 2; /* save allowed & perfect play */ 00120 if (url_is_streamed(s)) 00121 flags |= 4; /* live broadcast */ 00122 put_be16(s, flags); 00123 00124 /* comments */ 00125 00126 put_tag(s,"CONT"); 00127 size = 4 * 2 + 10; 00128 for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) { 00129 tag = av_metadata_get(ctx->metadata, ff_rm_metadata[i], NULL, 0); 00130 if(tag) size += strlen(tag->value); 00131 } 00132 put_be32(s,size); 00133 put_be16(s,0); 00134 for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) { 00135 tag = av_metadata_get(ctx->metadata, ff_rm_metadata[i], NULL, 0); 00136 put_str(s, tag ? tag->value : ""); 00137 } 00138 00139 for(i=0;i<ctx->nb_streams;i++) { 00140 int codec_data_size; 00141 00142 stream = &rm->streams[i]; 00143 00144 if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) { 00145 desc = "The Audio Stream"; 00146 mimetype = "audio/x-pn-realaudio"; 00147 codec_data_size = 73; 00148 } else { 00149 desc = "The Video Stream"; 00150 mimetype = "video/x-pn-realvideo"; 00151 codec_data_size = 34; 00152 } 00153 00154 put_tag(s,"MDPR"); 00155 size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size; 00156 put_be32(s, size); 00157 put_be16(s, 0); 00158 00159 put_be16(s, i); /* stream number */ 00160 put_be32(s, stream->bit_rate); /* max bit rate */ 00161 put_be32(s, stream->bit_rate); /* avg bit rate */ 00162 put_be32(s, stream->packet_max_size); /* max packet size */ 00163 if (stream->nb_packets > 0) 00164 packet_avg_size = stream->packet_total_size / 00165 stream->nb_packets; 00166 else 00167 packet_avg_size = 0; 00168 put_be32(s, packet_avg_size); /* avg packet size */ 00169 put_be32(s, 0); /* start time */ 00170 put_be32(s, BUFFER_DURATION); /* preroll */ 00171 /* duration */ 00172 if (url_is_streamed(s) || !stream->total_frames) 00173 put_be32(s, (int)(3600 * 1000)); 00174 else 00175 put_be32(s, (int)(stream->total_frames * 1000 / stream->frame_rate)); 00176 put_str8(s, desc); 00177 put_str8(s, mimetype); 00178 put_be32(s, codec_data_size); 00179 00180 if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) { 00181 int coded_frame_size, fscode, sample_rate; 00182 sample_rate = stream->enc->sample_rate; 00183 coded_frame_size = (stream->enc->bit_rate * 00184 stream->enc->frame_size) / (8 * sample_rate); 00185 /* audio codec info */ 00186 put_tag(s, ".ra"); 00187 put_byte(s, 0xfd); 00188 put_be32(s, 0x00040000); /* version */ 00189 put_tag(s, ".ra4"); 00190 put_be32(s, 0x01b53530); /* stream length */ 00191 put_be16(s, 4); /* unknown */ 00192 put_be32(s, 0x39); /* header size */ 00193 00194 switch(sample_rate) { 00195 case 48000: 00196 case 24000: 00197 case 12000: 00198 fscode = 1; 00199 break; 00200 default: 00201 case 44100: 00202 case 22050: 00203 case 11025: 00204 fscode = 2; 00205 break; 00206 case 32000: 00207 case 16000: 00208 case 8000: 00209 fscode = 3; 00210 } 00211 put_be16(s, fscode); /* codec additional info, for AC-3, seems 00212 to be a frequency code */ 00213 /* special hack to compensate rounding errors... */ 00214 if (coded_frame_size == 557) 00215 coded_frame_size--; 00216 put_be32(s, coded_frame_size); /* frame length */ 00217 put_be32(s, 0x51540); /* unknown */ 00218 put_be32(s, 0x249f0); /* unknown */ 00219 put_be32(s, 0x249f0); /* unknown */ 00220 put_be16(s, 0x01); 00221 /* frame length : seems to be very important */ 00222 put_be16(s, coded_frame_size); 00223 put_be32(s, 0); /* unknown */ 00224 put_be16(s, stream->enc->sample_rate); /* sample rate */ 00225 put_be32(s, 0x10); /* unknown */ 00226 put_be16(s, stream->enc->channels); 00227 put_str8(s, "Int0"); /* codec name */ 00228 put_str8(s, "dnet"); /* codec name */ 00229 put_be16(s, 0); /* title length */ 00230 put_be16(s, 0); /* author length */ 00231 put_be16(s, 0); /* copyright length */ 00232 put_byte(s, 0); /* end of header */ 00233 } else { 00234 /* video codec info */ 00235 put_be32(s,34); /* size */ 00236 if(stream->enc->codec_id == CODEC_ID_RV10) 00237 put_tag(s,"VIDORV10"); 00238 else 00239 put_tag(s,"VIDORV20"); 00240 put_be16(s, stream->enc->width); 00241 put_be16(s, stream->enc->height); 00242 put_be16(s, (int) stream->frame_rate); /* frames per seconds ? */ 00243 put_be32(s,0); /* unknown meaning */ 00244 put_be16(s, (int) stream->frame_rate); /* unknown meaning */ 00245 put_be32(s,0); /* unknown meaning */ 00246 put_be16(s, 8); /* unknown meaning */ 00247 /* Seems to be the codec version: only use basic H263. The next 00248 versions seems to add a diffential DC coding as in 00249 MPEG... nothing new under the sun */ 00250 if(stream->enc->codec_id == CODEC_ID_RV10) 00251 put_be32(s,0x10000000); 00252 else 00253 put_be32(s,0x20103001); 00254 //put_be32(s,0x10003000); 00255 } 00256 } 00257 00258 /* patch data offset field */ 00259 data_pos = s->buf_ptr - start_ptr; 00260 rm->data_pos = data_pos; 00261 data_offset_ptr[0] = data_pos >> 24; 00262 data_offset_ptr[1] = data_pos >> 16; 00263 data_offset_ptr[2] = data_pos >> 8; 00264 data_offset_ptr[3] = data_pos; 00265 00266 /* data stream */ 00267 put_tag(s,"DATA"); 00268 put_be32(s,data_size + 10 + 8); 00269 put_be16(s,0); 00270 00271 put_be32(s, nb_packets); /* number of packets */ 00272 put_be32(s,0); /* next data header */ 00273 } 00274 00275 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream, 00276 int length, int key_frame) 00277 { 00278 int timestamp; 00279 ByteIOContext *s = ctx->pb; 00280 00281 stream->nb_packets++; 00282 stream->packet_total_size += length; 00283 if (length > stream->packet_max_size) 00284 stream->packet_max_size = length; 00285 00286 put_be16(s,0); /* version */ 00287 put_be16(s,length + 12); 00288 put_be16(s, stream->num); /* stream number */ 00289 timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate; 00290 put_be32(s, timestamp); /* timestamp */ 00291 put_byte(s, 0); /* reserved */ 00292 put_byte(s, key_frame ? 2 : 0); /* flags */ 00293 } 00294 00295 static int rm_write_header(AVFormatContext *s) 00296 { 00297 RMMuxContext *rm = s->priv_data; 00298 StreamInfo *stream; 00299 int n; 00300 AVCodecContext *codec; 00301 00302 for(n=0;n<s->nb_streams;n++) { 00303 s->streams[n]->id = n; 00304 codec = s->streams[n]->codec; 00305 stream = &rm->streams[n]; 00306 memset(stream, 0, sizeof(StreamInfo)); 00307 stream->num = n; 00308 stream->bit_rate = codec->bit_rate; 00309 stream->enc = codec; 00310 00311 switch(codec->codec_type) { 00312 case AVMEDIA_TYPE_AUDIO: 00313 rm->audio_stream = stream; 00314 stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size; 00315 /* XXX: dummy values */ 00316 stream->packet_max_size = 1024; 00317 stream->nb_packets = 0; 00318 stream->total_frames = stream->nb_packets; 00319 break; 00320 case AVMEDIA_TYPE_VIDEO: 00321 rm->video_stream = stream; 00322 stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num; 00323 /* XXX: dummy values */ 00324 stream->packet_max_size = 4096; 00325 stream->nb_packets = 0; 00326 stream->total_frames = stream->nb_packets; 00327 break; 00328 default: 00329 return -1; 00330 } 00331 } 00332 00333 rv10_write_header(s, 0, 0); 00334 put_flush_packet(s->pb); 00335 return 0; 00336 } 00337 00338 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags) 00339 { 00340 uint8_t *buf1; 00341 RMMuxContext *rm = s->priv_data; 00342 ByteIOContext *pb = s->pb; 00343 StreamInfo *stream = rm->audio_stream; 00344 int i; 00345 00346 /* XXX: suppress this malloc */ 00347 buf1= (uint8_t*) av_malloc( size * sizeof(uint8_t) ); 00348 00349 write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY)); 00350 00351 /* for AC-3, the words seem to be reversed */ 00352 for(i=0;i<size;i+=2) { 00353 buf1[i] = buf[i+1]; 00354 buf1[i+1] = buf[i]; 00355 } 00356 put_buffer(pb, buf1, size); 00357 put_flush_packet(pb); 00358 stream->nb_frames++; 00359 av_free(buf1); 00360 return 0; 00361 } 00362 00363 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags) 00364 { 00365 RMMuxContext *rm = s->priv_data; 00366 ByteIOContext *pb = s->pb; 00367 StreamInfo *stream = rm->video_stream; 00368 int key_frame = !!(flags & AV_PKT_FLAG_KEY); 00369 00370 /* XXX: this is incorrect: should be a parameter */ 00371 00372 /* Well, I spent some time finding the meaning of these bits. I am 00373 not sure I understood everything, but it works !! */ 00374 #if 1 00375 write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame); 00376 /* bit 7: '1' if final packet of a frame converted in several packets */ 00377 put_byte(pb, 0x81); 00378 /* bit 7: '1' if I frame. bits 6..0 : sequence number in current 00379 frame starting from 1 */ 00380 if (key_frame) { 00381 put_byte(pb, 0x81); 00382 } else { 00383 put_byte(pb, 0x01); 00384 } 00385 if(size >= 0x4000){ 00386 put_be32(pb, size); /* total frame size */ 00387 put_be32(pb, size); /* offset from the start or the end */ 00388 }else{ 00389 put_be16(pb, 0x4000 | size); /* total frame size */ 00390 put_be16(pb, 0x4000 | size); /* offset from the start or the end */ 00391 } 00392 #else 00393 /* full frame */ 00394 write_packet_header(s, size + 6); 00395 put_byte(pb, 0xc0); 00396 put_be16(pb, 0x4000 + size); /* total frame size */ 00397 put_be16(pb, 0x4000 + packet_number * 126); /* position in stream */ 00398 #endif 00399 put_byte(pb, stream->nb_frames & 0xff); 00400 00401 put_buffer(pb, buf, size); 00402 put_flush_packet(pb); 00403 00404 stream->nb_frames++; 00405 return 0; 00406 } 00407 00408 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt) 00409 { 00410 if (s->streams[pkt->stream_index]->codec->codec_type == 00411 AVMEDIA_TYPE_AUDIO) 00412 return rm_write_audio(s, pkt->data, pkt->size, pkt->flags); 00413 else 00414 return rm_write_video(s, pkt->data, pkt->size, pkt->flags); 00415 } 00416 00417 static int rm_write_trailer(AVFormatContext *s) 00418 { 00419 RMMuxContext *rm = s->priv_data; 00420 int data_size, index_pos, i; 00421 ByteIOContext *pb = s->pb; 00422 00423 if (!url_is_streamed(s->pb)) { 00424 /* end of file: finish to write header */ 00425 index_pos = url_fseek(pb, 0, SEEK_CUR); 00426 data_size = index_pos - rm->data_pos; 00427 00428 /* FIXME: write index */ 00429 00430 /* undocumented end header */ 00431 put_be32(pb, 0); 00432 put_be32(pb, 0); 00433 00434 url_fseek(pb, 0, SEEK_SET); 00435 for(i=0;i<s->nb_streams;i++) 00436 rm->streams[i].total_frames = rm->streams[i].nb_frames; 00437 rv10_write_header(s, data_size, 0); 00438 } else { 00439 /* undocumented end header */ 00440 put_be32(pb, 0); 00441 put_be32(pb, 0); 00442 } 00443 put_flush_packet(pb); 00444 return 0; 00445 } 00446 00447 00448 AVOutputFormat rm_muxer = { 00449 "rm", 00450 NULL_IF_CONFIG_SMALL("RealMedia format"), 00451 "application/vnd.rn-realmedia", 00452 "rm,ra", 00453 sizeof(RMMuxContext), 00454 CODEC_ID_AC3, 00455 CODEC_ID_RV10, 00456 rm_write_header, 00457 rm_write_packet, 00458 rm_write_trailer, 00459 };