Libav 0.7.1
libavformat/nutenc.c
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00001 /*
00002  * nut muxer
00003  * Copyright (c) 2004-2007 Michael Niedermayer
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/intreadwrite.h"
00023 #include "libavutil/tree.h"
00024 #include "libavutil/dict.h"
00025 #include "libavcodec/mpegaudiodata.h"
00026 #include "nut.h"
00027 #include "internal.h"
00028 #include "avio_internal.h"
00029 
00030 static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
00031     int sample_rate= c->sample_rate;
00032 
00033     if(size>4096)
00034         return 0;
00035 
00036     AV_WB24(out, 1);
00037 
00038     if(c->codec_id == CODEC_ID_MPEG4){
00039         if(key_frame){
00040             return 3;
00041         }else{
00042             out[3]= 0xB6;
00043             return 4;
00044         }
00045     }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
00046         return 3;
00047     }else if(c->codec_id == CODEC_ID_H264){
00048         return 3;
00049     }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
00050         int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
00051         int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
00052         unsigned int header= 0xFFF00000;
00053 
00054         lsf     = sample_rate < (24000+32000)/2;
00055         mpeg25  = sample_rate < (12000+16000)/2;
00056         sample_rate <<= lsf + mpeg25;
00057         if     (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
00058         else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
00059         else                                     sample_rate_index=1;
00060 
00061         sample_rate= ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
00062 
00063         for(bitrate_index=2; bitrate_index<30; bitrate_index++){
00064             frame_size = ff_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
00065             frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
00066 
00067             if(frame_size == size)
00068                 break;
00069         }
00070 
00071         header |= (!lsf)<<19;
00072         header |= (4-layer)<<17;
00073         header |= 1<<16; //no crc
00074         AV_WB32(out, header);
00075         if(size <= 0)
00076             return 2; //we guess there is no crc, if there is one the user clearly does not care about overhead
00077         if(bitrate_index == 30)
00078             return -1; //something is wrong ...
00079 
00080         header |= (bitrate_index>>1)<<12;
00081         header |= sample_rate_index<<10;
00082         header |= (bitrate_index&1)<<9;
00083 
00084         return 2; //FIXME actually put the needed ones in build_elision_headers()
00085         return 3; //we guess that the private bit is not set
00086 //FIXME the above assumptions should be checked, if these turn out false too often something should be done
00087     }
00088     return 0;
00089 }
00090 
00091 static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
00092     NUTContext *nut = s->priv_data;
00093     uint8_t out[64];
00094     int i;
00095     int len= find_expected_header(c, size, frame_type, out);
00096 
00097 //av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
00098 
00099     for(i=1; i<nut->header_count; i++){
00100         if(   len == nut->header_len[i]
00101            && !memcmp(out, nut->header[i], len)){
00102 //    av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
00103             return i;
00104         }
00105     }
00106 //    av_log(NULL, AV_LOG_ERROR, "nothing found\n");
00107     return 0;
00108 }
00109 
00110 static void build_elision_headers(AVFormatContext *s){
00111     NUTContext *nut = s->priv_data;
00112     int i;
00113     //FIXME this is lame
00114     //FIXME write a 2pass mode to find the maximal headers
00115     static const uint8_t headers[][5]={
00116         {3, 0x00, 0x00, 0x01},
00117         {4, 0x00, 0x00, 0x01, 0xB6},
00118         {2, 0xFF, 0xFA}, //mp3+crc
00119         {2, 0xFF, 0xFB}, //mp3
00120         {2, 0xFF, 0xFC}, //mp2+crc
00121         {2, 0xFF, 0xFD}, //mp2
00122     };
00123 
00124     nut->header_count= 7;
00125     for(i=1; i<nut->header_count; i++){
00126         nut->header_len[i]=  headers[i-1][0];
00127         nut->header    [i]= &headers[i-1][1];
00128     }
00129 }
00130 
00131 static void build_frame_code(AVFormatContext *s){
00132     NUTContext *nut = s->priv_data;
00133     int key_frame, index, pred, stream_id;
00134     int start=1;
00135     int end= 254;
00136     int keyframe_0_esc= s->nb_streams > 2;
00137     int pred_table[10];
00138     FrameCode *ft;
00139 
00140     ft= &nut->frame_code[start];
00141     ft->flags= FLAG_CODED;
00142     ft->size_mul=1;
00143     ft->pts_delta=1;
00144     start++;
00145 
00146     if(keyframe_0_esc){
00147         /* keyframe = 0 escape */
00148         FrameCode *ft= &nut->frame_code[start];
00149         ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
00150         ft->size_mul=1;
00151         start++;
00152     }
00153 
00154     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
00155         int start2= start + (end-start)*stream_id / s->nb_streams;
00156         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
00157         AVCodecContext *codec = s->streams[stream_id]->codec;
00158         int is_audio= codec->codec_type == AVMEDIA_TYPE_AUDIO;
00159         int intra_only= /*codec->intra_only || */is_audio;
00160         int pred_count;
00161 
00162         for(key_frame=0; key_frame<2; key_frame++){
00163             if(intra_only && keyframe_0_esc && key_frame==0)
00164                 continue;
00165 
00166             {
00167                 FrameCode *ft= &nut->frame_code[start2];
00168                 ft->flags= FLAG_KEY*key_frame;
00169                 ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
00170                 ft->stream_id= stream_id;
00171                 ft->size_mul=1;
00172                 if(is_audio)
00173                     ft->header_idx= find_header_idx(s, codec, -1, key_frame);
00174                 start2++;
00175             }
00176         }
00177 
00178         key_frame= intra_only;
00179         if(is_audio){
00180             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
00181             int pts;
00182             for(pts=0; pts<2; pts++){
00183                 for(pred=0; pred<2; pred++){
00184                     FrameCode *ft= &nut->frame_code[start2];
00185                     ft->flags= FLAG_KEY*key_frame;
00186                     ft->stream_id= stream_id;
00187                     ft->size_mul=frame_bytes + 2;
00188                     ft->size_lsb=frame_bytes + pred;
00189                     ft->pts_delta=pts;
00190                     ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
00191                     start2++;
00192                 }
00193             }
00194         }else{
00195             FrameCode *ft= &nut->frame_code[start2];
00196             ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
00197             ft->stream_id= stream_id;
00198             ft->size_mul=1;
00199             ft->pts_delta=1;
00200             start2++;
00201         }
00202 
00203         if(codec->has_b_frames){
00204             pred_count=5;
00205             pred_table[0]=-2;
00206             pred_table[1]=-1;
00207             pred_table[2]=1;
00208             pred_table[3]=3;
00209             pred_table[4]=4;
00210         }else if(codec->codec_id == CODEC_ID_VORBIS){
00211             pred_count=3;
00212             pred_table[0]=2;
00213             pred_table[1]=9;
00214             pred_table[2]=16;
00215         }else{
00216             pred_count=1;
00217             pred_table[0]=1;
00218         }
00219 
00220         for(pred=0; pred<pred_count; pred++){
00221             int start3= start2 + (end2-start2)*pred / pred_count;
00222             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
00223 
00224             for(index=start3; index<end3; index++){
00225                 FrameCode *ft= &nut->frame_code[index];
00226                 ft->flags= FLAG_KEY*key_frame;
00227                 ft->flags|= FLAG_SIZE_MSB;
00228                 ft->stream_id= stream_id;
00229 //FIXME use single byte size and pred from last
00230                 ft->size_mul= end3-start3;
00231                 ft->size_lsb= index - start3;
00232                 ft->pts_delta= pred_table[pred];
00233                 if(is_audio)
00234                     ft->header_idx= find_header_idx(s, codec, -1, key_frame);
00235             }
00236         }
00237     }
00238     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
00239     nut->frame_code[  0].flags=
00240     nut->frame_code[255].flags=
00241     nut->frame_code['N'].flags= FLAG_INVALID;
00242 }
00243 
00244 static void put_tt(NUTContext *nut, AVRational *time_base, AVIOContext *bc, uint64_t val){
00245     val *= nut->time_base_count;
00246     val += time_base - nut->time_base;
00247     ff_put_v(bc, val);
00248 }
00249 
00253 static void put_str(AVIOContext *bc, const char *string){
00254     int len= strlen(string);
00255 
00256     ff_put_v(bc, len);
00257     avio_write(bc, string, len);
00258 }
00259 
00260 static void put_s(AVIOContext *bc, int64_t val){
00261     ff_put_v(bc, 2*FFABS(val) - (val>0));
00262 }
00263 
00264 #ifdef TRACE
00265 static inline void ff_put_v_trace(AVIOContext *bc, uint64_t v, char *file, char *func, int line){
00266     av_log(NULL, AV_LOG_DEBUG, "ff_put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00267 
00268     ff_put_v(bc, v);
00269 }
00270 
00271 static inline void put_s_trace(AVIOContext *bc, int64_t v, char *file, char *func, int line){
00272     av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00273 
00274     put_s(bc, v);
00275 }
00276 #define ff_put_v(bc, v)  ff_put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00277 #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00278 #endif
00279 
00280 //FIXME remove calculate_checksum
00281 static void put_packet(NUTContext *nut, AVIOContext *bc, AVIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
00282     uint8_t *dyn_buf=NULL;
00283     int dyn_size= avio_close_dyn_buf(dyn_bc, &dyn_buf);
00284     int forw_ptr= dyn_size + 4*calculate_checksum;
00285 
00286     if(forw_ptr > 4096)
00287         ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00288     avio_wb64(bc, startcode);
00289     ff_put_v(bc, forw_ptr);
00290     if(forw_ptr > 4096)
00291         avio_wl32(bc, ffio_get_checksum(bc));
00292 
00293     if(calculate_checksum)
00294         ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00295     avio_write(bc, dyn_buf, dyn_size);
00296     if(calculate_checksum)
00297         avio_wl32(bc, ffio_get_checksum(bc));
00298 
00299     av_free(dyn_buf);
00300 }
00301 
00302 static void write_mainheader(NUTContext *nut, AVIOContext *bc){
00303     int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
00304     int64_t tmp_match;
00305 
00306     ff_put_v(bc, 3); /* version */
00307     ff_put_v(bc, nut->avf->nb_streams);
00308     ff_put_v(bc, nut->max_distance);
00309     ff_put_v(bc, nut->time_base_count);
00310 
00311     for(i=0; i<nut->time_base_count; i++){
00312         ff_put_v(bc, nut->time_base[i].num);
00313         ff_put_v(bc, nut->time_base[i].den);
00314     }
00315 
00316     tmp_pts=0;
00317     tmp_mul=1;
00318     tmp_stream=0;
00319     tmp_match= 1-(1LL<<62);
00320     tmp_head_idx= 0;
00321     for(i=0; i<256;){
00322         tmp_fields=0;
00323         tmp_size=0;
00324 //        tmp_res=0;
00325         if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
00326         if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
00327         if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
00328         if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
00329 //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
00330         if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
00331 
00332         tmp_pts   = nut->frame_code[i].pts_delta;
00333         tmp_flags = nut->frame_code[i].flags;
00334         tmp_stream= nut->frame_code[i].stream_id;
00335         tmp_mul   = nut->frame_code[i].size_mul;
00336         tmp_size  = nut->frame_code[i].size_lsb;
00337 //        tmp_res   = nut->frame_code[i].res;
00338         tmp_head_idx= nut->frame_code[i].header_idx;
00339 
00340         for(j=0; i<256; j++,i++){
00341             if(i == 'N'){
00342                 j--;
00343                 continue;
00344             }
00345             if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
00346             if(nut->frame_code[i].flags     != tmp_flags ) break;
00347             if(nut->frame_code[i].stream_id != tmp_stream) break;
00348             if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
00349             if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
00350 //            if(nut->frame_code[i].res       != tmp_res   ) break;
00351             if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
00352         }
00353         if(j != tmp_mul - tmp_size) tmp_fields=6;
00354 
00355         ff_put_v(bc, tmp_flags);
00356         ff_put_v(bc, tmp_fields);
00357         if(tmp_fields>0) put_s(bc, tmp_pts);
00358         if(tmp_fields>1) ff_put_v(bc, tmp_mul);
00359         if(tmp_fields>2) ff_put_v(bc, tmp_stream);
00360         if(tmp_fields>3) ff_put_v(bc, tmp_size);
00361         if(tmp_fields>4) ff_put_v(bc, 0 /*tmp_res*/);
00362         if(tmp_fields>5) ff_put_v(bc, j);
00363         if(tmp_fields>6) ff_put_v(bc, tmp_match);
00364         if(tmp_fields>7) ff_put_v(bc, tmp_head_idx);
00365     }
00366     ff_put_v(bc, nut->header_count-1);
00367     for(i=1; i<nut->header_count; i++){
00368         ff_put_v(bc, nut->header_len[i]);
00369         avio_write(bc, nut->header[i], nut->header_len[i]);
00370     }
00371 }
00372 
00373 static int write_streamheader(AVFormatContext *avctx, AVIOContext *bc, AVStream *st, int i){
00374     NUTContext *nut = avctx->priv_data;
00375     AVCodecContext *codec = st->codec;
00376     ff_put_v(bc, i);
00377     switch(codec->codec_type){
00378     case AVMEDIA_TYPE_VIDEO: ff_put_v(bc, 0); break;
00379     case AVMEDIA_TYPE_AUDIO: ff_put_v(bc, 1); break;
00380     case AVMEDIA_TYPE_SUBTITLE: ff_put_v(bc, 2); break;
00381     default              : ff_put_v(bc, 3); break;
00382     }
00383     ff_put_v(bc, 4);
00384     if (codec->codec_tag){
00385         avio_wl32(bc, codec->codec_tag);
00386     } else {
00387         av_log(avctx, AV_LOG_ERROR, "No codec tag defined for stream %d\n", i);
00388         return AVERROR(EINVAL);
00389     }
00390 
00391     ff_put_v(bc, nut->stream[i].time_base - nut->time_base);
00392     ff_put_v(bc, nut->stream[i].msb_pts_shift);
00393     ff_put_v(bc, nut->stream[i].max_pts_distance);
00394     ff_put_v(bc, codec->has_b_frames);
00395     avio_w8(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
00396 
00397     ff_put_v(bc, codec->extradata_size);
00398     avio_write(bc, codec->extradata, codec->extradata_size);
00399 
00400     switch(codec->codec_type){
00401     case AVMEDIA_TYPE_AUDIO:
00402         ff_put_v(bc, codec->sample_rate);
00403         ff_put_v(bc, 1);
00404         ff_put_v(bc, codec->channels);
00405         break;
00406     case AVMEDIA_TYPE_VIDEO:
00407         ff_put_v(bc, codec->width);
00408         ff_put_v(bc, codec->height);
00409 
00410         if(st->sample_aspect_ratio.num<=0 || st->sample_aspect_ratio.den<=0){
00411             ff_put_v(bc, 0);
00412             ff_put_v(bc, 0);
00413         }else{
00414             ff_put_v(bc, st->sample_aspect_ratio.num);
00415             ff_put_v(bc, st->sample_aspect_ratio.den);
00416         }
00417         ff_put_v(bc, 0); /* csp type -- unknown */
00418         break;
00419     default:
00420         break;
00421     }
00422     return 0;
00423 }
00424 
00425 static int add_info(AVIOContext *bc, const char *type, const char *value){
00426     put_str(bc, type);
00427     put_s(bc, -1);
00428     put_str(bc, value);
00429     return 1;
00430 }
00431 
00432 static int write_globalinfo(NUTContext *nut, AVIOContext *bc){
00433     AVFormatContext *s= nut->avf;
00434     AVDictionaryEntry *t = NULL;
00435     AVIOContext *dyn_bc;
00436     uint8_t *dyn_buf=NULL;
00437     int count=0, dyn_size;
00438     int ret = avio_open_dyn_buf(&dyn_bc);
00439     if(ret < 0)
00440         return ret;
00441 
00442     while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
00443         count += add_info(dyn_bc, t->key, t->value);
00444 
00445     ff_put_v(bc, 0); //stream_if_plus1
00446     ff_put_v(bc, 0); //chapter_id
00447     ff_put_v(bc, 0); //timestamp_start
00448     ff_put_v(bc, 0); //length
00449 
00450     ff_put_v(bc, count);
00451 
00452     dyn_size= avio_close_dyn_buf(dyn_bc, &dyn_buf);
00453     avio_write(bc, dyn_buf, dyn_size);
00454     av_free(dyn_buf);
00455     return 0;
00456 }
00457 
00458 static int write_streaminfo(NUTContext *nut, AVIOContext *bc, int stream_id){
00459     AVFormatContext *s= nut->avf;
00460     AVStream* st = s->streams[stream_id];
00461     AVIOContext *dyn_bc;
00462     uint8_t *dyn_buf=NULL;
00463     int count=0, dyn_size, i;
00464     int ret = avio_open_dyn_buf(&dyn_bc);
00465     if(ret < 0)
00466         return ret;
00467 
00468     for (i=0; ff_nut_dispositions[i].flag; ++i) {
00469         if (st->disposition & ff_nut_dispositions[i].flag)
00470             count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
00471     }
00472     dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
00473 
00474     if (count) {
00475         ff_put_v(bc, stream_id + 1); //stream_id_plus1
00476         ff_put_v(bc, 0); //chapter_id
00477         ff_put_v(bc, 0); //timestamp_start
00478         ff_put_v(bc, 0); //length
00479 
00480         ff_put_v(bc, count);
00481 
00482         avio_write(bc, dyn_buf, dyn_size);
00483     }
00484 
00485     av_free(dyn_buf);
00486     return count;
00487 }
00488 
00489 static int write_chapter(NUTContext *nut, AVIOContext *bc, int id)
00490 {
00491     AVIOContext *dyn_bc;
00492     uint8_t *dyn_buf = NULL;
00493     AVDictionaryEntry *t = NULL;
00494     AVChapter *ch    = nut->avf->chapters[id];
00495     int ret, dyn_size, count = 0;
00496 
00497     ret = avio_open_dyn_buf(&dyn_bc);
00498     if (ret < 0)
00499         return ret;
00500 
00501     ff_put_v(bc, 0);                                        // stream_id_plus1
00502     put_s(bc, id + 1);                                      // chapter_id
00503     put_tt(nut, nut->chapter[id].time_base, bc, ch->start); // chapter_start
00504     ff_put_v(bc, ch->end - ch->start);                      // chapter_len
00505 
00506     while ((t = av_dict_get(ch->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
00507         count += add_info(dyn_bc, t->key, t->value);
00508 
00509     ff_put_v(bc, count);
00510 
00511     dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
00512     avio_write(bc, dyn_buf, dyn_size);
00513     av_freep(&dyn_buf);
00514     return 0;
00515 }
00516 
00517 static int write_headers(AVFormatContext *avctx, AVIOContext *bc){
00518     NUTContext *nut = avctx->priv_data;
00519     AVIOContext *dyn_bc;
00520     int i, ret;
00521 
00522     ff_metadata_conv_ctx(avctx, ff_nut_metadata_conv, NULL);
00523 
00524     ret = avio_open_dyn_buf(&dyn_bc);
00525     if(ret < 0)
00526         return ret;
00527     write_mainheader(nut, dyn_bc);
00528     put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
00529 
00530     for (i=0; i < nut->avf->nb_streams; i++){
00531         ret = avio_open_dyn_buf(&dyn_bc);
00532         if(ret < 0)
00533             return ret;
00534         if ((ret = write_streamheader(avctx, dyn_bc, nut->avf->streams[i], i)) < 0)
00535             return ret;
00536         put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
00537     }
00538 
00539     ret = avio_open_dyn_buf(&dyn_bc);
00540     if(ret < 0)
00541         return ret;
00542     write_globalinfo(nut, dyn_bc);
00543     put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00544 
00545     for (i = 0; i < nut->avf->nb_streams; i++) {
00546         ret = avio_open_dyn_buf(&dyn_bc);
00547         if(ret < 0)
00548             return ret;
00549         ret = write_streaminfo(nut, dyn_bc, i);
00550         if (ret < 0)
00551             return ret;
00552         if (ret > 0)
00553             put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00554         else {
00555             uint8_t* buf;
00556             avio_close_dyn_buf(dyn_bc, &buf);
00557             av_free(buf);
00558         }
00559     }
00560 
00561     for (i = 0; i < nut->avf->nb_chapters; i++) {
00562         ret = avio_open_dyn_buf(&dyn_bc);
00563         if (ret < 0)
00564             return ret;
00565         ret = write_chapter(nut, dyn_bc, i);
00566         if (ret < 0) {
00567             uint8_t *buf;
00568             avio_close_dyn_buf(dyn_bc, &buf);
00569             av_freep(&buf);
00570             return ret;
00571         }
00572         put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00573     }
00574 
00575     nut->last_syncpoint_pos= INT_MIN;
00576     nut->header_count++;
00577     return 0;
00578 }
00579 
00580 static int write_header(AVFormatContext *s){
00581     NUTContext *nut = s->priv_data;
00582     AVIOContext *bc = s->pb;
00583     int i, j, ret;
00584 
00585     nut->avf= s;
00586 
00587     nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
00588     if (s->nb_chapters)
00589         nut->chapter  = av_mallocz(sizeof(ChapterContext)*s->nb_chapters);
00590     nut->time_base= av_mallocz(sizeof(AVRational   )*(s->nb_streams +
00591                                                       s->nb_chapters));
00592     if (!nut->stream || (s->nb_chapters && !nut->chapter) || !nut->time_base) {
00593         av_freep(&nut->stream);
00594         av_freep(&nut->chapter);
00595         av_freep(&nut->time_base);
00596         return AVERROR(ENOMEM);
00597     }
00598 
00599     for(i=0; i<s->nb_streams; i++){
00600         AVStream *st= s->streams[i];
00601         int ssize;
00602         AVRational time_base;
00603         ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
00604 
00605         av_set_pts_info(st, 64, time_base.num, time_base.den);
00606 
00607         for(j=0; j<nut->time_base_count; j++){
00608             if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
00609                 break;
00610             }
00611         }
00612         nut->time_base[j]= time_base;
00613         nut->stream[i].time_base= &nut->time_base[j];
00614         if(j==nut->time_base_count)
00615             nut->time_base_count++;
00616 
00617         if(INT64_C(1000) * time_base.num >= time_base.den)
00618             nut->stream[i].msb_pts_shift = 7;
00619         else
00620             nut->stream[i].msb_pts_shift = 14;
00621         nut->stream[i].max_pts_distance= FFMAX(time_base.den, time_base.num) / time_base.num;
00622     }
00623 
00624     for (i = 0; i < s->nb_chapters; i++) {
00625         AVChapter *ch = s->chapters[i];
00626 
00627         for (j = 0; j < nut->time_base_count; j++) {
00628             if (!memcmp(&ch->time_base, &nut->time_base[j], sizeof(AVRational)))
00629                 break;
00630         }
00631 
00632         nut->time_base[j] = ch->time_base;
00633         nut->chapter[i].time_base = &nut->time_base[j];
00634         if(j == nut->time_base_count)
00635             nut->time_base_count++;
00636     }
00637 
00638     nut->max_distance = MAX_DISTANCE;
00639     build_elision_headers(s);
00640     build_frame_code(s);
00641     assert(nut->frame_code['N'].flags == FLAG_INVALID);
00642 
00643     avio_write(bc, ID_STRING, strlen(ID_STRING));
00644     avio_w8(bc, 0);
00645 
00646     if ((ret = write_headers(s, bc)) < 0)
00647         return ret;
00648 
00649     avio_flush(bc);
00650 
00651     //FIXME index
00652 
00653     return 0;
00654 }
00655 
00656 static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
00657     int flags= 0;
00658 
00659     if(pkt->flags & AV_PKT_FLAG_KEY             ) flags |= FLAG_KEY;
00660     if(pkt->stream_index != fc->stream_id       ) flags |= FLAG_STREAM_ID;
00661     if(pkt->size / fc->size_mul                 ) flags |= FLAG_SIZE_MSB;
00662     if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
00663     if(pkt->size > 2*nut->max_distance          ) flags |= FLAG_CHECKSUM;
00664     if(FFABS(pkt->pts - nus->last_pts)
00665                          > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
00666     if(   pkt->size < nut->header_len[fc->header_idx]
00667        || (pkt->size > 4096 && fc->header_idx)
00668        || memcmp(pkt->data, nut->header[fc->header_idx], nut->header_len[fc->header_idx]))
00669                                                   flags |= FLAG_HEADER_IDX;
00670 
00671     return flags | (fc->flags & FLAG_CODED);
00672 }
00673 
00674 static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
00675     int i;
00676     int best_i  = 0;
00677     int best_len= 0;
00678 
00679     if(pkt->size > 4096)
00680         return 0;
00681 
00682     for(i=1; i<nut->header_count; i++){
00683         if(   pkt->size >= nut->header_len[i]
00684            &&  nut->header_len[i] > best_len
00685            && !memcmp(pkt->data, nut->header[i], nut->header_len[i])){
00686             best_i= i;
00687             best_len= nut->header_len[i];
00688         }
00689     }
00690     return best_i;
00691 }
00692 
00693 static int write_packet(AVFormatContext *s, AVPacket *pkt){
00694     NUTContext *nut = s->priv_data;
00695     StreamContext *nus= &nut->stream[pkt->stream_index];
00696     AVIOContext *bc = s->pb, *dyn_bc;
00697     FrameCode *fc;
00698     int64_t coded_pts;
00699     int best_length, frame_code, flags, needed_flags, i, header_idx, best_header_idx;
00700     int key_frame = !!(pkt->flags & AV_PKT_FLAG_KEY);
00701     int store_sp=0;
00702     int ret;
00703 
00704     if(pkt->pts < 0)
00705         return -1;
00706 
00707     if(1LL<<(20+3*nut->header_count) <= avio_tell(bc))
00708         write_headers(s, bc);
00709 
00710     if(key_frame && !(nus->last_flags & FLAG_KEY))
00711         store_sp= 1;
00712 
00713     if(pkt->size + 30/*FIXME check*/ + avio_tell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
00714         store_sp= 1;
00715 
00716 //FIXME: Ensure store_sp is 1 in the first place.
00717 
00718     if(store_sp){
00719         Syncpoint *sp, dummy= {.pos= INT64_MAX};
00720 
00721         ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
00722         for(i=0; i<s->nb_streams; i++){
00723             AVStream *st= s->streams[i];
00724             int64_t dts_tb = av_rescale_rnd(pkt->dts,
00725                 nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
00726                 nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
00727                 AV_ROUND_DOWN);
00728             int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
00729             if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
00730         }
00731         if(dummy.pos == INT64_MAX)
00732             dummy.pos= 0;
00733         sp= av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00734                          NULL);
00735 
00736         nut->last_syncpoint_pos= avio_tell(bc);
00737         ret = avio_open_dyn_buf(&dyn_bc);
00738         if(ret < 0)
00739             return ret;
00740         put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
00741         ff_put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
00742         put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
00743 
00744         ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
00745     }
00746     assert(nus->last_pts != AV_NOPTS_VALUE);
00747 
00748     coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
00749     if(ff_lsb2full(nus, coded_pts) != pkt->pts)
00750         coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
00751 
00752     best_header_idx= find_best_header_idx(nut, pkt);
00753 
00754     best_length=INT_MAX;
00755     frame_code= -1;
00756     for(i=0; i<256; i++){
00757         int length= 0;
00758         FrameCode *fc= &nut->frame_code[i];
00759         int flags= fc->flags;
00760 
00761         if(flags & FLAG_INVALID)
00762             continue;
00763         needed_flags= get_needed_flags(nut, nus, fc, pkt);
00764 
00765         if(flags & FLAG_CODED){
00766             length++;
00767             flags = needed_flags;
00768         }
00769 
00770         if((flags & needed_flags) != needed_flags)
00771             continue;
00772 
00773         if((flags ^ needed_flags) & FLAG_KEY)
00774             continue;
00775 
00776         if(flags & FLAG_STREAM_ID)
00777             length+= ff_get_v_length(pkt->stream_index);
00778 
00779         if(pkt->size % fc->size_mul != fc->size_lsb)
00780             continue;
00781         if(flags & FLAG_SIZE_MSB)
00782             length += ff_get_v_length(pkt->size / fc->size_mul);
00783 
00784         if(flags & FLAG_CHECKSUM)
00785             length+=4;
00786 
00787         if(flags & FLAG_CODED_PTS)
00788             length += ff_get_v_length(coded_pts);
00789 
00790         if(   (flags & FLAG_CODED)
00791            && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
00792             flags |= FLAG_HEADER_IDX;
00793         }
00794 
00795         if(flags & FLAG_HEADER_IDX){
00796             length += 1 - nut->header_len[best_header_idx];
00797         }else{
00798             length -= nut->header_len[fc->header_idx];
00799         }
00800 
00801         length*=4;
00802         length+= !(flags & FLAG_CODED_PTS);
00803         length+= !(flags & FLAG_CHECKSUM);
00804 
00805         if(length < best_length){
00806             best_length= length;
00807             frame_code=i;
00808         }
00809     }
00810     assert(frame_code != -1);
00811     fc= &nut->frame_code[frame_code];
00812     flags= fc->flags;
00813     needed_flags= get_needed_flags(nut, nus, fc, pkt);
00814     header_idx= fc->header_idx;
00815 
00816     ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00817     avio_w8(bc, frame_code);
00818     if(flags & FLAG_CODED){
00819         ff_put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
00820         flags = needed_flags;
00821     }
00822     if(flags & FLAG_STREAM_ID)  ff_put_v(bc, pkt->stream_index);
00823     if(flags & FLAG_CODED_PTS)  ff_put_v(bc, coded_pts);
00824     if(flags & FLAG_SIZE_MSB)   ff_put_v(bc, pkt->size / fc->size_mul);
00825     if(flags & FLAG_HEADER_IDX) ff_put_v(bc, header_idx= best_header_idx);
00826 
00827     if(flags & FLAG_CHECKSUM)   avio_wl32(bc, ffio_get_checksum(bc));
00828     else                        ffio_get_checksum(bc);
00829 
00830     avio_write(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
00831     nus->last_flags= flags;
00832     nus->last_pts= pkt->pts;
00833 
00834     //FIXME just store one per syncpoint
00835     if(flags & FLAG_KEY)
00836         av_add_index_entry(
00837             s->streams[pkt->stream_index],
00838             nut->last_syncpoint_pos,
00839             pkt->pts,
00840             0,
00841             0,
00842             AVINDEX_KEYFRAME);
00843 
00844     return 0;
00845 }
00846 
00847 static int write_trailer(AVFormatContext *s){
00848     NUTContext *nut= s->priv_data;
00849     AVIOContext *bc= s->pb;
00850 
00851     while(nut->header_count<3)
00852         write_headers(s, bc);
00853     avio_flush(bc);
00854     ff_nut_free_sp(nut);
00855     av_freep(&nut->stream);
00856     av_freep(&nut->chapter);
00857     av_freep(&nut->time_base);
00858 
00859     return 0;
00860 }
00861 
00862 AVOutputFormat ff_nut_muxer = {
00863     "nut",
00864     NULL_IF_CONFIG_SMALL("NUT format"),
00865     "video/x-nut",
00866     "nut",
00867     sizeof(NUTContext),
00868 #if   CONFIG_LIBVORBIS
00869     CODEC_ID_VORBIS,
00870 #elif CONFIG_LIBMP3LAME
00871     CODEC_ID_MP3,
00872 #else
00873     CODEC_ID_MP2,
00874 #endif
00875     CODEC_ID_MPEG4,
00876     write_header,
00877     write_packet,
00878     write_trailer,
00879     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
00880     .codec_tag = (const AVCodecTag * const []){ ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
00881 };