3 * Copyright (c) 2004-2007 Michael Niedermayer
5 * This file is part of FFmpeg.
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.
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.
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
24 #include "mpegaudiodata.h"
26 static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
27 int sample_rate= c->sample_rate;
34 if(c->codec_id == CODEC_ID_MPEG4){
41 }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
43 }else if(c->codec_id == CODEC_ID_H264){
45 }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
46 int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
47 int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
48 unsigned int header= 0xFFF00000;
50 lsf = sample_rate < (24000+32000)/2;
51 mpeg25 = sample_rate < (12000+16000)/2;
52 sample_rate <<= lsf + mpeg25;
53 if (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
54 else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
55 else sample_rate_index=1;
57 sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
59 for(bitrate_index=2; bitrate_index<30; bitrate_index++){
60 frame_size = ff_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
61 frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
63 if(frame_size == size)
68 header |= (4-layer)<<17;
69 header |= 1<<16; //no crc
72 return 2; //we guess theres no crc, if there is one the user clearly doesnt care about overhead
73 if(bitrate_index == 30)
74 return -1; //something is wrong ...
76 header |= (bitrate_index>>1)<<12;
77 header |= sample_rate_index<<10;
78 header |= (bitrate_index&1)<<9;
80 return 2; //FIXME actually put the needed ones in build_elision_headers()
81 return 3; //we guess that the private bit isnt set
82 //FIXME the above asumtations should be checked, if these turn out false too often something should be done
87 static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
88 NUTContext *nut = s->priv_data;
91 int len= find_expected_header(c, size, frame_type, out);
93 //av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
95 for(i=1; i<nut->header_count; i++){
96 if( len == nut->header_len[i]
97 && !memcmp(out, nut->header[i], len)){
98 // av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
102 // av_log(NULL, AV_LOG_ERROR, "nothing found\n");
106 static void build_elision_headers(AVFormatContext *s){
107 NUTContext *nut = s->priv_data;
110 //FIXME write a 2pass mode to find the maximal headers
111 const static uint8_t headers[][5]={
112 {3, 0x00, 0x00, 0x01},
113 {4, 0x00, 0x00, 0x01, 0xB6},
114 {2, 0xFF, 0xFA}, //mp3+crc
115 {2, 0xFF, 0xFB}, //mp3
116 {2, 0xFF, 0xFC}, //mp2+crc
117 {2, 0xFF, 0xFD}, //mp2
120 nut->header_count= 7;
121 for(i=1; i<nut->header_count; i++){
122 nut->header_len[i]= headers[i-1][0];
123 nut->header [i]= &headers[i-1][1];
127 static void build_frame_code(AVFormatContext *s){
128 NUTContext *nut = s->priv_data;
129 int key_frame, index, pred, stream_id;
132 int keyframe_0_esc= s->nb_streams > 2;
136 ft= &nut->frame_code[start];
137 ft->flags= FLAG_CODED;
143 /* keyframe = 0 escape */
144 FrameCode *ft= &nut->frame_code[start];
145 ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
150 for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
151 int start2= start + (end-start)*stream_id / s->nb_streams;
152 int end2 = start + (end-start)*(stream_id+1) / s->nb_streams;
153 AVCodecContext *codec = s->streams[stream_id]->codec;
154 int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
155 int intra_only= /*codec->intra_only || */is_audio;
158 for(key_frame=0; key_frame<2; key_frame++){
159 if(intra_only && keyframe_0_esc && key_frame==0)
163 FrameCode *ft= &nut->frame_code[start2];
164 ft->flags= FLAG_KEY*key_frame;
165 ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
166 ft->stream_id= stream_id;
169 ft->header_idx= find_header_idx(s, codec, -1, key_frame);
174 key_frame= intra_only;
177 int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
179 for(pts=0; pts<2; pts++){
180 for(pred=0; pred<2; pred++){
181 FrameCode *ft= &nut->frame_code[start2];
182 ft->flags= FLAG_KEY*key_frame;
183 ft->stream_id= stream_id;
184 ft->size_mul=frame_bytes + 2;
185 ft->size_lsb=frame_bytes + pred;
187 ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
192 FrameCode *ft= &nut->frame_code[start2];
193 ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
194 ft->stream_id= stream_id;
201 if(codec->has_b_frames){
208 }else if(codec->codec_id == CODEC_ID_VORBIS){
218 for(pred=0; pred<pred_count; pred++){
219 int start3= start2 + (end2-start2)*pred / pred_count;
220 int end3 = start2 + (end2-start2)*(pred+1) / pred_count;
222 for(index=start3; index<end3; index++){
223 FrameCode *ft= &nut->frame_code[index];
224 ft->flags= FLAG_KEY*key_frame;
225 ft->flags|= FLAG_SIZE_MSB;
226 ft->stream_id= stream_id;
227 //FIXME use single byte size and pred from last
228 ft->size_mul= end3-start3;
229 ft->size_lsb= index - start3;
230 ft->pts_delta= pred_table[pred];
232 ft->header_idx= find_header_idx(s, codec, -1, key_frame);
236 memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
237 nut->frame_code[ 0].flags=
238 nut->frame_code[255].flags=
239 nut->frame_code['N'].flags= FLAG_INVALID;
243 * Gets the length in bytes which is needed to store val as v.
245 static int get_length(uint64_t val){
254 static void put_v(ByteIOContext *bc, uint64_t val){
255 int i= get_length(val);
258 put_byte(bc, 128 | (val>>(7*i)));
260 put_byte(bc, val&127);
263 static void put_t(NUTContext *nut, StreamContext *nus, ByteIOContext *bc, uint64_t val){
264 val *= nut->time_base_count;
265 val += nus->time_base - nut->time_base;
270 * Stores a string as vb.
272 static void put_str(ByteIOContext *bc, const char *string){
273 int len= strlen(string);
276 put_buffer(bc, string, len);
279 static void put_s(ByteIOContext *bc, int64_t val){
280 put_v(bc, 2*FFABS(val) - (val>0));
284 static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
285 av_log(NULL, AV_LOG_DEBUG, "put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
290 static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
291 av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
295 #define put_v(bc, v) put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
296 #define put_s(bc, v) put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
299 //FIXME remove calculate_checksum
300 static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
301 uint8_t *dyn_buf=NULL;
302 int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
303 int forw_ptr= dyn_size + 4*calculate_checksum;
306 init_checksum(bc, ff_crc04C11DB7_update, 0);
307 put_be64(bc, startcode);
310 put_le32(bc, get_checksum(bc));
312 if(calculate_checksum)
313 init_checksum(bc, ff_crc04C11DB7_update, 0);
314 put_buffer(bc, dyn_buf, dyn_size);
315 if(calculate_checksum)
316 put_le32(bc, get_checksum(bc));
321 static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
322 int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
325 put_v(bc, 3); /* version */
326 put_v(bc, nut->avf->nb_streams);
327 put_v(bc, nut->max_distance);
328 put_v(bc, nut->time_base_count);
330 for(i=0; i<nut->time_base_count; i++){
331 put_v(bc, nut->time_base[i].num);
332 put_v(bc, nut->time_base[i].den);
338 tmp_match= 1-(1LL<<62);
344 if(tmp_pts != nut->frame_code[i].pts_delta) tmp_fields=1;
345 if(tmp_mul != nut->frame_code[i].size_mul ) tmp_fields=2;
346 if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
347 if(tmp_size != nut->frame_code[i].size_lsb ) tmp_fields=4;
348 // if(tmp_res != nut->frame_code[i].res ) tmp_fields=5;
349 if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
351 tmp_pts = nut->frame_code[i].pts_delta;
352 tmp_flags = nut->frame_code[i].flags;
353 tmp_stream= nut->frame_code[i].stream_id;
354 tmp_mul = nut->frame_code[i].size_mul;
355 tmp_size = nut->frame_code[i].size_lsb;
356 // tmp_res = nut->frame_code[i].res;
357 tmp_head_idx= nut->frame_code[i].header_idx;
359 for(j=0; i<256; j++,i++){
364 if(nut->frame_code[i].pts_delta != tmp_pts ) break;
365 if(nut->frame_code[i].flags != tmp_flags ) break;
366 if(nut->frame_code[i].stream_id != tmp_stream) break;
367 if(nut->frame_code[i].size_mul != tmp_mul ) break;
368 if(nut->frame_code[i].size_lsb != tmp_size+j) break;
369 // if(nut->frame_code[i].res != tmp_res ) break;
370 if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
372 if(j != tmp_mul - tmp_size) tmp_fields=6;
374 put_v(bc, tmp_flags);
375 put_v(bc, tmp_fields);
376 if(tmp_fields>0) put_s(bc, tmp_pts);
377 if(tmp_fields>1) put_v(bc, tmp_mul);
378 if(tmp_fields>2) put_v(bc, tmp_stream);
379 if(tmp_fields>3) put_v(bc, tmp_size);
380 if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
381 if(tmp_fields>5) put_v(bc, j);
382 if(tmp_fields>6) put_v(bc, tmp_match);
383 if(tmp_fields>7) put_v(bc, tmp_head_idx);
385 put_v(bc, nut->header_count-1);
386 for(i=1; i<nut->header_count; i++){
387 put_v(bc, nut->header_len[i]);
388 put_buffer(bc, nut->header[i], nut->header_len[i]);
392 static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
394 switch(codec->codec_type){
395 case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
396 case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
397 // case CODEC_TYPE_TEXT : put_v(bc, 2); break;
398 default : put_v(bc, 3); break;
401 if (codec->codec_tag){
402 put_le32(bc, codec->codec_tag);
406 put_v(bc, nut->stream[i].time_base - nut->time_base);
407 put_v(bc, nut->stream[i].msb_pts_shift);
408 put_v(bc, nut->stream[i].max_pts_distance);
409 put_v(bc, codec->has_b_frames);
410 put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
412 put_v(bc, codec->extradata_size);
413 put_buffer(bc, codec->extradata, codec->extradata_size);
415 switch(codec->codec_type){
416 case CODEC_TYPE_AUDIO:
417 put_v(bc, codec->sample_rate);
419 put_v(bc, codec->channels);
421 case CODEC_TYPE_VIDEO:
422 put_v(bc, codec->width);
423 put_v(bc, codec->height);
425 if(codec->sample_aspect_ratio.num<=0 || codec->sample_aspect_ratio.den<=0){
429 put_v(bc, codec->sample_aspect_ratio.num);
430 put_v(bc, codec->sample_aspect_ratio.den);
432 put_v(bc, 0); /* csp type -- unknown */
440 static int add_info(ByteIOContext *bc, const char *type, const char *value){
447 static int write_globalinfo(NUTContext *nut, ByteIOContext *bc){
448 AVFormatContext *s= nut->avf;
449 ByteIOContext *dyn_bc;
450 uint8_t *dyn_buf=NULL;
451 int count=0, dyn_size;
452 int ret = url_open_dyn_buf(&dyn_bc);
456 if(s->title [0]) count+= add_info(dyn_bc, "Title" , s->title);
457 if(s->author [0]) count+= add_info(dyn_bc, "Author" , s->author);
458 if(s->copyright[0]) count+= add_info(dyn_bc, "Copyright", s->copyright);
459 if(!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT))
460 count+= add_info(dyn_bc, "Encoder" , LIBAVFORMAT_IDENT);
462 put_v(bc, 0); //stream_if_plus1
463 put_v(bc, 0); //chapter_id
464 put_v(bc, 0); //timestamp_start
465 put_v(bc, 0); //length
469 dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
470 put_buffer(bc, dyn_buf, dyn_size);
475 static int write_headers(NUTContext *nut, ByteIOContext *bc){
476 ByteIOContext *dyn_bc;
479 ret = url_open_dyn_buf(&dyn_bc);
482 write_mainheader(nut, dyn_bc);
483 put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
485 for (i=0; i < nut->avf->nb_streams; i++){
486 AVCodecContext *codec = nut->avf->streams[i]->codec;
488 ret = url_open_dyn_buf(&dyn_bc);
491 write_streamheader(nut, dyn_bc, codec, i);
492 put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
495 ret = url_open_dyn_buf(&dyn_bc);
498 write_globalinfo(nut, dyn_bc);
499 put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
501 nut->last_syncpoint_pos= INT_MIN;
506 static int write_header(AVFormatContext *s){
507 NUTContext *nut = s->priv_data;
508 ByteIOContext *bc = s->pb;
513 nut->stream = av_mallocz(sizeof(StreamContext)*s->nb_streams);
514 nut->time_base= av_mallocz(sizeof(AVRational )*s->nb_streams);
516 for(i=0; i<s->nb_streams; i++){
517 AVStream *st= s->streams[i];
519 AVRational time_base;
520 ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
522 av_set_pts_info(st, 64, time_base.num, time_base.den);
524 for(j=0; j<nut->time_base_count; j++){
525 if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
529 nut->time_base[j]= time_base;
530 nut->stream[i].time_base= &nut->time_base[j];
531 if(j==nut->time_base_count)
532 nut->time_base_count++;
534 if(av_q2d(time_base) >= 0.001)
535 nut->stream[i].msb_pts_shift = 7;
537 nut->stream[i].msb_pts_shift = 14;
538 nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
541 nut->max_distance = MAX_DISTANCE;
542 build_elision_headers(s);
544 assert(nut->frame_code['N'].flags == FLAG_INVALID);
546 put_buffer(bc, ID_STRING, strlen(ID_STRING));
549 write_headers(nut, bc);
551 put_flush_packet(bc);
558 static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
561 if(pkt->flags & PKT_FLAG_KEY ) flags |= FLAG_KEY;
562 if(pkt->stream_index != fc->stream_id ) flags |= FLAG_STREAM_ID;
563 if(pkt->size / fc->size_mul ) flags |= FLAG_SIZE_MSB;
564 if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
565 if(pkt->size > 2*nut->max_distance ) flags |= FLAG_CHECKSUM;
566 if(FFABS(pkt->pts - nus->last_pts)
567 > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
568 if( pkt->size < nut->header_len[fc->header_idx]
569 || (pkt->size > 4096 && fc->header_idx)
570 || memcmp(pkt->data, nut->header[fc->header_idx], nut->header_len[fc->header_idx]))
571 flags |= FLAG_HEADER_IDX;
573 return flags | (fc->flags & FLAG_CODED);
576 static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
584 for(i=1; i<nut->header_count; i++){
585 if( pkt->size >= nut->header_len[i]
586 && nut->header_len[i] > best_len
587 && !memcmp(pkt->data, nut->header[i], nut->header_len[i])){
589 best_len= nut->header_len[i];
595 static int write_packet(AVFormatContext *s, AVPacket *pkt){
596 NUTContext *nut = s->priv_data;
597 StreamContext *nus= &nut->stream[pkt->stream_index];
598 ByteIOContext *bc = s->pb, *dyn_bc;
601 int best_length, frame_code, flags, needed_flags, i, header_idx, best_header_idx;
602 int key_frame = !!(pkt->flags & PKT_FLAG_KEY);
606 if(1LL<<(20+3*nut->header_count) <= url_ftell(bc))
607 write_headers(nut, bc);
609 if(key_frame && !(nus->last_flags & FLAG_KEY))
612 if(pkt->size + 30/*FIXME check*/ + url_ftell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
615 //FIXME: Ensure store_sp is 1 in the first place.
618 syncpoint_t *sp, dummy= {.pos= INT64_MAX};
620 ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
621 for(i=0; i<s->nb_streams; i++){
622 AVStream *st= s->streams[i];
623 int64_t dts_tb = av_rescale_rnd(pkt->dts,
624 nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
625 nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
627 int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
628 if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
630 if(dummy.pos == INT64_MAX)
632 sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
634 nut->last_syncpoint_pos= url_ftell(bc);
635 ret = url_open_dyn_buf(&dyn_bc);
638 put_t(nut, nus, dyn_bc, pkt->dts);
639 put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
640 put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
642 ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
644 assert(nus->last_pts != AV_NOPTS_VALUE);
646 coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
647 if(ff_lsb2full(nus, coded_pts) != pkt->pts)
648 coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
650 best_header_idx= find_best_header_idx(nut, pkt);
654 for(i=0; i<256; i++){
656 FrameCode *fc= &nut->frame_code[i];
657 int flags= fc->flags;
659 if(flags & FLAG_INVALID)
661 needed_flags= get_needed_flags(nut, nus, fc, pkt);
663 if(flags & FLAG_CODED){
665 flags = needed_flags;
668 if((flags & needed_flags) != needed_flags)
671 if((flags ^ needed_flags) & FLAG_KEY)
674 if(flags & FLAG_STREAM_ID)
675 length+= get_length(pkt->stream_index);
677 if(pkt->size % fc->size_mul != fc->size_lsb)
679 if(flags & FLAG_SIZE_MSB)
680 length += get_length(pkt->size / fc->size_mul);
682 if(flags & FLAG_CHECKSUM)
685 if(flags & FLAG_CODED_PTS)
686 length += get_length(coded_pts);
688 if( (flags & FLAG_CODED)
689 && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
690 flags |= FLAG_HEADER_IDX;
693 if(flags & FLAG_HEADER_IDX){
694 length += 1 - nut->header_len[best_header_idx];
696 length -= nut->header_len[fc->header_idx];
700 length+= !(flags & FLAG_CODED_PTS);
701 length+= !(flags & FLAG_CHECKSUM);
703 if(length < best_length){
708 assert(frame_code != -1);
709 fc= &nut->frame_code[frame_code];
711 needed_flags= get_needed_flags(nut, nus, fc, pkt);
712 header_idx= fc->header_idx;
714 init_checksum(bc, ff_crc04C11DB7_update, 0);
715 put_byte(bc, frame_code);
716 if(flags & FLAG_CODED){
717 put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
718 flags = needed_flags;
720 if(flags & FLAG_STREAM_ID) put_v(bc, pkt->stream_index);
721 if(flags & FLAG_CODED_PTS) put_v(bc, coded_pts);
722 if(flags & FLAG_SIZE_MSB) put_v(bc, pkt->size / fc->size_mul);
723 if(flags & FLAG_HEADER_IDX) put_v(bc, header_idx= best_header_idx);
725 if(flags & FLAG_CHECKSUM) put_le32(bc, get_checksum(bc));
726 else get_checksum(bc);
728 put_buffer(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
729 nus->last_flags= flags;
730 nus->last_pts= pkt->pts;
732 //FIXME just store one per syncpoint
735 s->streams[pkt->stream_index],
736 nut->last_syncpoint_pos,
745 static int write_trailer(AVFormatContext *s){
746 NUTContext *nut= s->priv_data;
747 ByteIOContext *bc= s->pb;
749 while(nut->header_count<3)
750 write_headers(nut, bc);
751 put_flush_packet(bc);
756 AVOutputFormat nut_muxer = {
762 #ifdef CONFIG_LIBVORBIS
764 #elif defined(CONFIG_LIBMP3LAME)
767 CODEC_ID_MP2, /* AC3 needs liba52 decoder */
773 .flags = AVFMT_GLOBALHEADER,
774 .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},