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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/mathematics.h"
00024 #include "libavutil/tree.h"
00025 #include "libavutil/dict.h"
00026 #include "libavcodec/mpegaudiodata.h"
00027 #include "nut.h"
00028 #include "internal.h"
00029 #include "avio_internal.h"
00030 
00031 static int find_expected_header(AVCodecContext *c, int size, int key_frame, uint8_t out[64]){
00032     int sample_rate= c->sample_rate;
00033 
00034     if(size>4096)
00035         return 0;
00036 
00037     AV_WB24(out, 1);
00038 
00039     if(c->codec_id == CODEC_ID_MPEG4){
00040         if(key_frame){
00041             return 3;
00042         }else{
00043             out[3]= 0xB6;
00044             return 4;
00045         }
00046     }else if(c->codec_id == CODEC_ID_MPEG1VIDEO || c->codec_id == CODEC_ID_MPEG2VIDEO){
00047         return 3;
00048     }else if(c->codec_id == CODEC_ID_H264){
00049         return 3;
00050     }else if(c->codec_id == CODEC_ID_MP3 || c->codec_id == CODEC_ID_MP2){
00051         int lsf, mpeg25, sample_rate_index, bitrate_index, frame_size;
00052         int layer= c->codec_id == CODEC_ID_MP3 ? 3 : 2;
00053         unsigned int header= 0xFFF00000;
00054 
00055         lsf     = sample_rate < (24000+32000)/2;
00056         mpeg25  = sample_rate < (12000+16000)/2;
00057         sample_rate <<= lsf + mpeg25;
00058         if     (sample_rate < (32000 + 44100)/2) sample_rate_index=2;
00059         else if(sample_rate < (44100 + 48000)/2) sample_rate_index=0;
00060         else                                     sample_rate_index=1;
00061 
00062         sample_rate= avpriv_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25);
00063 
00064         for(bitrate_index=2; bitrate_index<30; bitrate_index++){
00065             frame_size = avpriv_mpa_bitrate_tab[lsf][layer-1][bitrate_index>>1];
00066             frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
00067 
00068             if(frame_size == size)
00069                 break;
00070         }
00071 
00072         header |= (!lsf)<<19;
00073         header |= (4-layer)<<17;
00074         header |= 1<<16; //no crc
00075         AV_WB32(out, header);
00076         if(size <= 0)
00077             return 2; //we guess there is no crc, if there is one the user clearly does not care about overhead
00078         if(bitrate_index == 30)
00079             return -1; //something is wrong ...
00080 
00081         header |= (bitrate_index>>1)<<12;
00082         header |= sample_rate_index<<10;
00083         header |= (bitrate_index&1)<<9;
00084 
00085         return 2; //FIXME actually put the needed ones in build_elision_headers()
00086         return 3; //we guess that the private bit is not set
00087 //FIXME the above assumptions should be checked, if these turn out false too often something should be done
00088     }
00089     return 0;
00090 }
00091 
00092 static int find_header_idx(AVFormatContext *s, AVCodecContext *c, int size, int frame_type){
00093     NUTContext *nut = s->priv_data;
00094     uint8_t out[64];
00095     int i;
00096     int len= find_expected_header(c, size, frame_type, out);
00097 
00098 //av_log(NULL, AV_LOG_ERROR, "expected_h len=%d size=%d codec_id=%d\n", len, size, c->codec_id);
00099 
00100     for(i=1; i<nut->header_count; i++){
00101         if(   len == nut->header_len[i]
00102            && !memcmp(out, nut->header[i], len)){
00103 //    av_log(NULL, AV_LOG_ERROR, "found %d\n", i);
00104             return i;
00105         }
00106     }
00107 //    av_log(NULL, AV_LOG_ERROR, "nothing found\n");
00108     return 0;
00109 }
00110 
00111 static void build_elision_headers(AVFormatContext *s){
00112     NUTContext *nut = s->priv_data;
00113     int i;
00114     //FIXME this is lame
00115     //FIXME write a 2pass mode to find the maximal headers
00116     static const uint8_t headers[][5]={
00117         {3, 0x00, 0x00, 0x01},
00118         {4, 0x00, 0x00, 0x01, 0xB6},
00119         {2, 0xFF, 0xFA}, //mp3+crc
00120         {2, 0xFF, 0xFB}, //mp3
00121         {2, 0xFF, 0xFC}, //mp2+crc
00122         {2, 0xFF, 0xFD}, //mp2
00123     };
00124 
00125     nut->header_count= 7;
00126     for(i=1; i<nut->header_count; i++){
00127         nut->header_len[i]=  headers[i-1][0];
00128         nut->header    [i]= &headers[i-1][1];
00129     }
00130 }
00131 
00132 static void build_frame_code(AVFormatContext *s){
00133     NUTContext *nut = s->priv_data;
00134     int key_frame, index, pred, stream_id;
00135     int start=1;
00136     int end= 254;
00137     int keyframe_0_esc= s->nb_streams > 2;
00138     int pred_table[10];
00139     FrameCode *ft;
00140 
00141     ft= &nut->frame_code[start];
00142     ft->flags= FLAG_CODED;
00143     ft->size_mul=1;
00144     ft->pts_delta=1;
00145     start++;
00146 
00147     if(keyframe_0_esc){
00148         /* keyframe = 0 escape */
00149         FrameCode *ft= &nut->frame_code[start];
00150         ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
00151         ft->size_mul=1;
00152         start++;
00153     }
00154 
00155     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
00156         int start2= start + (end-start)*stream_id / s->nb_streams;
00157         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
00158         AVCodecContext *codec = s->streams[stream_id]->codec;
00159         int is_audio= codec->codec_type == AVMEDIA_TYPE_AUDIO;
00160         int intra_only= /*codec->intra_only || */is_audio;
00161         int pred_count;
00162 
00163         for(key_frame=0; key_frame<2; key_frame++){
00164             if(intra_only && keyframe_0_esc && key_frame==0)
00165                 continue;
00166 
00167             {
00168                 FrameCode *ft= &nut->frame_code[start2];
00169                 ft->flags= FLAG_KEY*key_frame;
00170                 ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
00171                 ft->stream_id= stream_id;
00172                 ft->size_mul=1;
00173                 if(is_audio)
00174                     ft->header_idx= find_header_idx(s, codec, -1, key_frame);
00175                 start2++;
00176             }
00177         }
00178 
00179         key_frame= intra_only;
00180         if(is_audio){
00181             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
00182             int pts;
00183             for(pts=0; pts<2; pts++){
00184                 for(pred=0; pred<2; pred++){
00185                     FrameCode *ft= &nut->frame_code[start2];
00186                     ft->flags= FLAG_KEY*key_frame;
00187                     ft->stream_id= stream_id;
00188                     ft->size_mul=frame_bytes + 2;
00189                     ft->size_lsb=frame_bytes + pred;
00190                     ft->pts_delta=pts;
00191                     ft->header_idx= find_header_idx(s, codec, frame_bytes + pred, key_frame);
00192                     start2++;
00193                 }
00194             }
00195         }else{
00196             FrameCode *ft= &nut->frame_code[start2];
00197             ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
00198             ft->stream_id= stream_id;
00199             ft->size_mul=1;
00200             ft->pts_delta=1;
00201             start2++;
00202         }
00203 
00204         if(codec->has_b_frames){
00205             pred_count=5;
00206             pred_table[0]=-2;
00207             pred_table[1]=-1;
00208             pred_table[2]=1;
00209             pred_table[3]=3;
00210             pred_table[4]=4;
00211         }else if(codec->codec_id == CODEC_ID_VORBIS){
00212             pred_count=3;
00213             pred_table[0]=2;
00214             pred_table[1]=9;
00215             pred_table[2]=16;
00216         }else{
00217             pred_count=1;
00218             pred_table[0]=1;
00219         }
00220 
00221         for(pred=0; pred<pred_count; pred++){
00222             int start3= start2 + (end2-start2)*pred / pred_count;
00223             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
00224 
00225             for(index=start3; index<end3; index++){
00226                 FrameCode *ft= &nut->frame_code[index];
00227                 ft->flags= FLAG_KEY*key_frame;
00228                 ft->flags|= FLAG_SIZE_MSB;
00229                 ft->stream_id= stream_id;
00230 //FIXME use single byte size and pred from last
00231                 ft->size_mul= end3-start3;
00232                 ft->size_lsb= index - start3;
00233                 ft->pts_delta= pred_table[pred];
00234                 if(is_audio)
00235                     ft->header_idx= find_header_idx(s, codec, -1, key_frame);
00236             }
00237         }
00238     }
00239     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
00240     nut->frame_code[  0].flags=
00241     nut->frame_code[255].flags=
00242     nut->frame_code['N'].flags= FLAG_INVALID;
00243 }
00244 
00245 static void put_tt(NUTContext *nut, AVRational *time_base, AVIOContext *bc, uint64_t val){
00246     val *= nut->time_base_count;
00247     val += time_base - nut->time_base;
00248     ff_put_v(bc, val);
00249 }
00250 
00254 static void put_str(AVIOContext *bc, const char *string){
00255     int len= strlen(string);
00256 
00257     ff_put_v(bc, len);
00258     avio_write(bc, string, len);
00259 }
00260 
00261 static void put_s(AVIOContext *bc, int64_t val){
00262     ff_put_v(bc, 2*FFABS(val) - (val>0));
00263 }
00264 
00265 #ifdef TRACE
00266 static inline void ff_put_v_trace(AVIOContext *bc, uint64_t v, char *file, char *func, int line){
00267     av_log(NULL, AV_LOG_DEBUG, "ff_put_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00268 
00269     ff_put_v(bc, v);
00270 }
00271 
00272 static inline void put_s_trace(AVIOContext *bc, int64_t v, char *file, char *func, int line){
00273     av_log(NULL, AV_LOG_DEBUG, "put_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
00274 
00275     put_s(bc, v);
00276 }
00277 #define ff_put_v(bc, v)  ff_put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00278 #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
00279 #endif
00280 
00281 //FIXME remove calculate_checksum
00282 static void put_packet(NUTContext *nut, AVIOContext *bc, AVIOContext *dyn_bc, int calculate_checksum, uint64_t startcode){
00283     uint8_t *dyn_buf=NULL;
00284     int dyn_size= avio_close_dyn_buf(dyn_bc, &dyn_buf);
00285     int forw_ptr= dyn_size + 4*calculate_checksum;
00286 
00287     if(forw_ptr > 4096)
00288         ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00289     avio_wb64(bc, startcode);
00290     ff_put_v(bc, forw_ptr);
00291     if(forw_ptr > 4096)
00292         avio_wl32(bc, ffio_get_checksum(bc));
00293 
00294     if(calculate_checksum)
00295         ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00296     avio_write(bc, dyn_buf, dyn_size);
00297     if(calculate_checksum)
00298         avio_wl32(bc, ffio_get_checksum(bc));
00299 
00300     av_free(dyn_buf);
00301 }
00302 
00303 static void write_mainheader(NUTContext *nut, AVIOContext *bc){
00304     int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields, tmp_head_idx;
00305     int64_t tmp_match;
00306 
00307     ff_put_v(bc, 3); /* version */
00308     ff_put_v(bc, nut->avf->nb_streams);
00309     ff_put_v(bc, nut->max_distance);
00310     ff_put_v(bc, nut->time_base_count);
00311 
00312     for(i=0; i<nut->time_base_count; i++){
00313         ff_put_v(bc, nut->time_base[i].num);
00314         ff_put_v(bc, nut->time_base[i].den);
00315     }
00316 
00317     tmp_pts=0;
00318     tmp_mul=1;
00319     tmp_stream=0;
00320     tmp_match= 1-(1LL<<62);
00321     tmp_head_idx= 0;
00322     for(i=0; i<256;){
00323         tmp_fields=0;
00324         tmp_size=0;
00325 //        tmp_res=0;
00326         if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
00327         if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
00328         if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
00329         if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
00330 //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
00331         if(tmp_head_idx!=nut->frame_code[i].header_idx)tmp_fields=8;
00332 
00333         tmp_pts   = nut->frame_code[i].pts_delta;
00334         tmp_flags = nut->frame_code[i].flags;
00335         tmp_stream= nut->frame_code[i].stream_id;
00336         tmp_mul   = nut->frame_code[i].size_mul;
00337         tmp_size  = nut->frame_code[i].size_lsb;
00338 //        tmp_res   = nut->frame_code[i].res;
00339         tmp_head_idx= nut->frame_code[i].header_idx;
00340 
00341         for(j=0; i<256; j++,i++){
00342             if(i == 'N'){
00343                 j--;
00344                 continue;
00345             }
00346             if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
00347             if(nut->frame_code[i].flags     != tmp_flags ) break;
00348             if(nut->frame_code[i].stream_id != tmp_stream) break;
00349             if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
00350             if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
00351 //            if(nut->frame_code[i].res       != tmp_res   ) break;
00352             if(nut->frame_code[i].header_idx!= tmp_head_idx) break;
00353         }
00354         if(j != tmp_mul - tmp_size) tmp_fields=6;
00355 
00356         ff_put_v(bc, tmp_flags);
00357         ff_put_v(bc, tmp_fields);
00358         if(tmp_fields>0) put_s(bc, tmp_pts);
00359         if(tmp_fields>1) ff_put_v(bc, tmp_mul);
00360         if(tmp_fields>2) ff_put_v(bc, tmp_stream);
00361         if(tmp_fields>3) ff_put_v(bc, tmp_size);
00362         if(tmp_fields>4) ff_put_v(bc, 0 /*tmp_res*/);
00363         if(tmp_fields>5) ff_put_v(bc, j);
00364         if(tmp_fields>6) ff_put_v(bc, tmp_match);
00365         if(tmp_fields>7) ff_put_v(bc, tmp_head_idx);
00366     }
00367     ff_put_v(bc, nut->header_count-1);
00368     for(i=1; i<nut->header_count; i++){
00369         ff_put_v(bc, nut->header_len[i]);
00370         avio_write(bc, nut->header[i], nut->header_len[i]);
00371     }
00372 }
00373 
00374 static int write_streamheader(AVFormatContext *avctx, AVIOContext *bc, AVStream *st, int i){
00375     NUTContext *nut = avctx->priv_data;
00376     AVCodecContext *codec = st->codec;
00377     ff_put_v(bc, i);
00378     switch(codec->codec_type){
00379     case AVMEDIA_TYPE_VIDEO: ff_put_v(bc, 0); break;
00380     case AVMEDIA_TYPE_AUDIO: ff_put_v(bc, 1); break;
00381     case AVMEDIA_TYPE_SUBTITLE: ff_put_v(bc, 2); break;
00382     default              : ff_put_v(bc, 3); break;
00383     }
00384     ff_put_v(bc, 4);
00385     if (codec->codec_tag){
00386         avio_wl32(bc, codec->codec_tag);
00387     } else {
00388         av_log(avctx, AV_LOG_ERROR, "No codec tag defined for stream %d\n", i);
00389         return AVERROR(EINVAL);
00390     }
00391 
00392     ff_put_v(bc, nut->stream[i].time_base - nut->time_base);
00393     ff_put_v(bc, nut->stream[i].msb_pts_shift);
00394     ff_put_v(bc, nut->stream[i].max_pts_distance);
00395     ff_put_v(bc, codec->has_b_frames);
00396     avio_w8(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
00397 
00398     ff_put_v(bc, codec->extradata_size);
00399     avio_write(bc, codec->extradata, codec->extradata_size);
00400 
00401     switch(codec->codec_type){
00402     case AVMEDIA_TYPE_AUDIO:
00403         ff_put_v(bc, codec->sample_rate);
00404         ff_put_v(bc, 1);
00405         ff_put_v(bc, codec->channels);
00406         break;
00407     case AVMEDIA_TYPE_VIDEO:
00408         ff_put_v(bc, codec->width);
00409         ff_put_v(bc, codec->height);
00410 
00411         if(st->sample_aspect_ratio.num<=0 || st->sample_aspect_ratio.den<=0){
00412             ff_put_v(bc, 0);
00413             ff_put_v(bc, 0);
00414         }else{
00415             ff_put_v(bc, st->sample_aspect_ratio.num);
00416             ff_put_v(bc, st->sample_aspect_ratio.den);
00417         }
00418         ff_put_v(bc, 0); /* csp type -- unknown */
00419         break;
00420     default:
00421         break;
00422     }
00423     return 0;
00424 }
00425 
00426 static int add_info(AVIOContext *bc, const char *type, const char *value){
00427     put_str(bc, type);
00428     put_s(bc, -1);
00429     put_str(bc, value);
00430     return 1;
00431 }
00432 
00433 static int write_globalinfo(NUTContext *nut, AVIOContext *bc){
00434     AVFormatContext *s= nut->avf;
00435     AVDictionaryEntry *t = NULL;
00436     AVIOContext *dyn_bc;
00437     uint8_t *dyn_buf=NULL;
00438     int count=0, dyn_size;
00439     int ret = avio_open_dyn_buf(&dyn_bc);
00440     if(ret < 0)
00441         return ret;
00442 
00443     while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
00444         count += add_info(dyn_bc, t->key, t->value);
00445 
00446     ff_put_v(bc, 0); //stream_if_plus1
00447     ff_put_v(bc, 0); //chapter_id
00448     ff_put_v(bc, 0); //timestamp_start
00449     ff_put_v(bc, 0); //length
00450 
00451     ff_put_v(bc, count);
00452 
00453     dyn_size= avio_close_dyn_buf(dyn_bc, &dyn_buf);
00454     avio_write(bc, dyn_buf, dyn_size);
00455     av_free(dyn_buf);
00456     return 0;
00457 }
00458 
00459 static int write_streaminfo(NUTContext *nut, AVIOContext *bc, int stream_id){
00460     AVFormatContext *s= nut->avf;
00461     AVStream* st = s->streams[stream_id];
00462     AVIOContext *dyn_bc;
00463     uint8_t *dyn_buf=NULL;
00464     int count=0, dyn_size, i;
00465     int ret = avio_open_dyn_buf(&dyn_bc);
00466     if(ret < 0)
00467         return ret;
00468 
00469     for (i=0; ff_nut_dispositions[i].flag; ++i) {
00470         if (st->disposition & ff_nut_dispositions[i].flag)
00471             count += add_info(dyn_bc, "Disposition", ff_nut_dispositions[i].str);
00472     }
00473     dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
00474 
00475     if (count) {
00476         ff_put_v(bc, stream_id + 1); //stream_id_plus1
00477         ff_put_v(bc, 0); //chapter_id
00478         ff_put_v(bc, 0); //timestamp_start
00479         ff_put_v(bc, 0); //length
00480 
00481         ff_put_v(bc, count);
00482 
00483         avio_write(bc, dyn_buf, dyn_size);
00484     }
00485 
00486     av_free(dyn_buf);
00487     return count;
00488 }
00489 
00490 static int write_chapter(NUTContext *nut, AVIOContext *bc, int id)
00491 {
00492     AVIOContext *dyn_bc;
00493     uint8_t *dyn_buf = NULL;
00494     AVDictionaryEntry *t = NULL;
00495     AVChapter *ch    = nut->avf->chapters[id];
00496     int ret, dyn_size, count = 0;
00497 
00498     ret = avio_open_dyn_buf(&dyn_bc);
00499     if (ret < 0)
00500         return ret;
00501 
00502     ff_put_v(bc, 0);                                        // stream_id_plus1
00503     put_s(bc, id + 1);                                      // chapter_id
00504     put_tt(nut, nut->chapter[id].time_base, bc, ch->start); // chapter_start
00505     ff_put_v(bc, ch->end - ch->start);                      // chapter_len
00506 
00507     while ((t = av_dict_get(ch->metadata, "", t, AV_DICT_IGNORE_SUFFIX)))
00508         count += add_info(dyn_bc, t->key, t->value);
00509 
00510     ff_put_v(bc, count);
00511 
00512     dyn_size = avio_close_dyn_buf(dyn_bc, &dyn_buf);
00513     avio_write(bc, dyn_buf, dyn_size);
00514     av_freep(&dyn_buf);
00515     return 0;
00516 }
00517 
00518 static int write_headers(AVFormatContext *avctx, AVIOContext *bc){
00519     NUTContext *nut = avctx->priv_data;
00520     AVIOContext *dyn_bc;
00521     int i, ret;
00522 
00523     ff_metadata_conv_ctx(avctx, ff_nut_metadata_conv, NULL);
00524 
00525     ret = avio_open_dyn_buf(&dyn_bc);
00526     if(ret < 0)
00527         return ret;
00528     write_mainheader(nut, dyn_bc);
00529     put_packet(nut, bc, dyn_bc, 1, MAIN_STARTCODE);
00530 
00531     for (i=0; i < nut->avf->nb_streams; i++){
00532         ret = avio_open_dyn_buf(&dyn_bc);
00533         if(ret < 0)
00534             return ret;
00535         if ((ret = write_streamheader(avctx, dyn_bc, nut->avf->streams[i], i)) < 0)
00536             return ret;
00537         put_packet(nut, bc, dyn_bc, 1, STREAM_STARTCODE);
00538     }
00539 
00540     ret = avio_open_dyn_buf(&dyn_bc);
00541     if(ret < 0)
00542         return ret;
00543     write_globalinfo(nut, dyn_bc);
00544     put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00545 
00546     for (i = 0; i < nut->avf->nb_streams; i++) {
00547         ret = avio_open_dyn_buf(&dyn_bc);
00548         if(ret < 0)
00549             return ret;
00550         ret = write_streaminfo(nut, dyn_bc, i);
00551         if (ret < 0)
00552             return ret;
00553         if (ret > 0)
00554             put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00555         else {
00556             uint8_t* buf;
00557             avio_close_dyn_buf(dyn_bc, &buf);
00558             av_free(buf);
00559         }
00560     }
00561 
00562     for (i = 0; i < nut->avf->nb_chapters; i++) {
00563         ret = avio_open_dyn_buf(&dyn_bc);
00564         if (ret < 0)
00565             return ret;
00566         ret = write_chapter(nut, dyn_bc, i);
00567         if (ret < 0) {
00568             uint8_t *buf;
00569             avio_close_dyn_buf(dyn_bc, &buf);
00570             av_freep(&buf);
00571             return ret;
00572         }
00573         put_packet(nut, bc, dyn_bc, 1, INFO_STARTCODE);
00574     }
00575 
00576     nut->last_syncpoint_pos= INT_MIN;
00577     nut->header_count++;
00578     return 0;
00579 }
00580 
00581 static int nut_write_header(AVFormatContext *s){
00582     NUTContext *nut = s->priv_data;
00583     AVIOContext *bc = s->pb;
00584     int i, j, ret;
00585 
00586     nut->avf= s;
00587 
00588     nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
00589     if (s->nb_chapters)
00590         nut->chapter  = av_mallocz(sizeof(ChapterContext)*s->nb_chapters);
00591     nut->time_base= av_mallocz(sizeof(AVRational   )*(s->nb_streams +
00592                                                       s->nb_chapters));
00593     if (!nut->stream || (s->nb_chapters && !nut->chapter) || !nut->time_base) {
00594         av_freep(&nut->stream);
00595         av_freep(&nut->chapter);
00596         av_freep(&nut->time_base);
00597         return AVERROR(ENOMEM);
00598     }
00599 
00600     for(i=0; i<s->nb_streams; i++){
00601         AVStream *st= s->streams[i];
00602         int ssize;
00603         AVRational time_base;
00604         ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
00605 
00606         avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
00607 
00608         for(j=0; j<nut->time_base_count; j++){
00609             if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
00610                 break;
00611             }
00612         }
00613         nut->time_base[j]= time_base;
00614         nut->stream[i].time_base= &nut->time_base[j];
00615         if(j==nut->time_base_count)
00616             nut->time_base_count++;
00617 
00618         if(INT64_C(1000) * time_base.num >= time_base.den)
00619             nut->stream[i].msb_pts_shift = 7;
00620         else
00621             nut->stream[i].msb_pts_shift = 14;
00622         nut->stream[i].max_pts_distance= FFMAX(time_base.den, time_base.num) / time_base.num;
00623     }
00624 
00625     for (i = 0; i < s->nb_chapters; i++) {
00626         AVChapter *ch = s->chapters[i];
00627 
00628         for (j = 0; j < nut->time_base_count; j++) {
00629             if (!memcmp(&ch->time_base, &nut->time_base[j], sizeof(AVRational)))
00630                 break;
00631         }
00632 
00633         nut->time_base[j] = ch->time_base;
00634         nut->chapter[i].time_base = &nut->time_base[j];
00635         if(j == nut->time_base_count)
00636             nut->time_base_count++;
00637     }
00638 
00639     nut->max_distance = MAX_DISTANCE;
00640     build_elision_headers(s);
00641     build_frame_code(s);
00642     assert(nut->frame_code['N'].flags == FLAG_INVALID);
00643 
00644     avio_write(bc, ID_STRING, strlen(ID_STRING));
00645     avio_w8(bc, 0);
00646 
00647     if ((ret = write_headers(s, bc)) < 0)
00648         return ret;
00649 
00650     avio_flush(bc);
00651 
00652     //FIXME index
00653 
00654     return 0;
00655 }
00656 
00657 static int get_needed_flags(NUTContext *nut, StreamContext *nus, FrameCode *fc, AVPacket *pkt){
00658     int flags= 0;
00659 
00660     if(pkt->flags & AV_PKT_FLAG_KEY             ) flags |= FLAG_KEY;
00661     if(pkt->stream_index != fc->stream_id       ) flags |= FLAG_STREAM_ID;
00662     if(pkt->size / fc->size_mul                 ) flags |= FLAG_SIZE_MSB;
00663     if(pkt->pts - nus->last_pts != fc->pts_delta) flags |= FLAG_CODED_PTS;
00664     if(pkt->size > 2*nut->max_distance          ) flags |= FLAG_CHECKSUM;
00665     if(FFABS(pkt->pts - nus->last_pts)
00666                          > nus->max_pts_distance) flags |= FLAG_CHECKSUM;
00667     if(   pkt->size < nut->header_len[fc->header_idx]
00668        || (pkt->size > 4096 && fc->header_idx)
00669        || memcmp(pkt->data, nut->header[fc->header_idx], nut->header_len[fc->header_idx]))
00670                                                   flags |= FLAG_HEADER_IDX;
00671 
00672     return flags | (fc->flags & FLAG_CODED);
00673 }
00674 
00675 static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
00676     int i;
00677     int best_i  = 0;
00678     int best_len= 0;
00679 
00680     if(pkt->size > 4096)
00681         return 0;
00682 
00683     for(i=1; i<nut->header_count; i++){
00684         if(   pkt->size >= nut->header_len[i]
00685            &&  nut->header_len[i] > best_len
00686            && !memcmp(pkt->data, nut->header[i], nut->header_len[i])){
00687             best_i= i;
00688             best_len= nut->header_len[i];
00689         }
00690     }
00691     return best_i;
00692 }
00693 
00694 static int nut_write_packet(AVFormatContext *s, AVPacket *pkt){
00695     NUTContext *nut = s->priv_data;
00696     StreamContext *nus= &nut->stream[pkt->stream_index];
00697     AVIOContext *bc = s->pb, *dyn_bc;
00698     FrameCode *fc;
00699     int64_t coded_pts;
00700     int best_length, frame_code, flags, needed_flags, i, header_idx, best_header_idx;
00701     int key_frame = !!(pkt->flags & AV_PKT_FLAG_KEY);
00702     int store_sp=0;
00703     int ret;
00704 
00705     if(pkt->pts < 0)
00706         return -1;
00707 
00708     if(1LL<<(20+3*nut->header_count) <= avio_tell(bc))
00709         write_headers(s, bc);
00710 
00711     if(key_frame && !(nus->last_flags & FLAG_KEY))
00712         store_sp= 1;
00713 
00714     if(pkt->size + 30/*FIXME check*/ + avio_tell(bc) >= nut->last_syncpoint_pos + nut->max_distance)
00715         store_sp= 1;
00716 
00717 //FIXME: Ensure store_sp is 1 in the first place.
00718 
00719     if(store_sp){
00720         Syncpoint *sp, dummy= {.pos= INT64_MAX};
00721 
00722         ff_nut_reset_ts(nut, *nus->time_base, pkt->dts);
00723         for(i=0; i<s->nb_streams; i++){
00724             AVStream *st= s->streams[i];
00725             int64_t dts_tb = av_rescale_rnd(pkt->dts,
00726                 nus->time_base->num * (int64_t)nut->stream[i].time_base->den,
00727                 nus->time_base->den * (int64_t)nut->stream[i].time_base->num,
00728                 AV_ROUND_DOWN);
00729             int index= av_index_search_timestamp(st, dts_tb, AVSEEK_FLAG_BACKWARD);
00730             if(index>=0) dummy.pos= FFMIN(dummy.pos, st->index_entries[index].pos);
00731         }
00732         if(dummy.pos == INT64_MAX)
00733             dummy.pos= 0;
00734         sp= av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,
00735                          NULL);
00736 
00737         nut->last_syncpoint_pos= avio_tell(bc);
00738         ret = avio_open_dyn_buf(&dyn_bc);
00739         if(ret < 0)
00740             return ret;
00741         put_tt(nut, nus->time_base, dyn_bc, pkt->dts);
00742         ff_put_v(dyn_bc, sp ? (nut->last_syncpoint_pos - sp->pos)>>4 : 0);
00743         put_packet(nut, bc, dyn_bc, 1, SYNCPOINT_STARTCODE);
00744 
00745         ff_nut_add_sp(nut, nut->last_syncpoint_pos, 0/*unused*/, pkt->dts);
00746     }
00747     assert(nus->last_pts != AV_NOPTS_VALUE);
00748 
00749     coded_pts = pkt->pts & ((1<<nus->msb_pts_shift)-1);
00750     if(ff_lsb2full(nus, coded_pts) != pkt->pts)
00751         coded_pts= pkt->pts + (1<<nus->msb_pts_shift);
00752 
00753     best_header_idx= find_best_header_idx(nut, pkt);
00754 
00755     best_length=INT_MAX;
00756     frame_code= -1;
00757     for(i=0; i<256; i++){
00758         int length= 0;
00759         FrameCode *fc= &nut->frame_code[i];
00760         int flags= fc->flags;
00761 
00762         if(flags & FLAG_INVALID)
00763             continue;
00764         needed_flags= get_needed_flags(nut, nus, fc, pkt);
00765 
00766         if(flags & FLAG_CODED){
00767             length++;
00768             flags = needed_flags;
00769         }
00770 
00771         if((flags & needed_flags) != needed_flags)
00772             continue;
00773 
00774         if((flags ^ needed_flags) & FLAG_KEY)
00775             continue;
00776 
00777         if(flags & FLAG_STREAM_ID)
00778             length+= ff_get_v_length(pkt->stream_index);
00779 
00780         if(pkt->size % fc->size_mul != fc->size_lsb)
00781             continue;
00782         if(flags & FLAG_SIZE_MSB)
00783             length += ff_get_v_length(pkt->size / fc->size_mul);
00784 
00785         if(flags & FLAG_CHECKSUM)
00786             length+=4;
00787 
00788         if(flags & FLAG_CODED_PTS)
00789             length += ff_get_v_length(coded_pts);
00790 
00791         if(   (flags & FLAG_CODED)
00792            && nut->header_len[best_header_idx] > nut->header_len[fc->header_idx]+1){
00793             flags |= FLAG_HEADER_IDX;
00794         }
00795 
00796         if(flags & FLAG_HEADER_IDX){
00797             length += 1 - nut->header_len[best_header_idx];
00798         }else{
00799             length -= nut->header_len[fc->header_idx];
00800         }
00801 
00802         length*=4;
00803         length+= !(flags & FLAG_CODED_PTS);
00804         length+= !(flags & FLAG_CHECKSUM);
00805 
00806         if(length < best_length){
00807             best_length= length;
00808             frame_code=i;
00809         }
00810     }
00811     assert(frame_code != -1);
00812     fc= &nut->frame_code[frame_code];
00813     flags= fc->flags;
00814     needed_flags= get_needed_flags(nut, nus, fc, pkt);
00815     header_idx= fc->header_idx;
00816 
00817     ffio_init_checksum(bc, ff_crc04C11DB7_update, 0);
00818     avio_w8(bc, frame_code);
00819     if(flags & FLAG_CODED){
00820         ff_put_v(bc, (flags^needed_flags) & ~(FLAG_CODED));
00821         flags = needed_flags;
00822     }
00823     if(flags & FLAG_STREAM_ID)  ff_put_v(bc, pkt->stream_index);
00824     if(flags & FLAG_CODED_PTS)  ff_put_v(bc, coded_pts);
00825     if(flags & FLAG_SIZE_MSB)   ff_put_v(bc, pkt->size / fc->size_mul);
00826     if(flags & FLAG_HEADER_IDX) ff_put_v(bc, header_idx= best_header_idx);
00827 
00828     if(flags & FLAG_CHECKSUM)   avio_wl32(bc, ffio_get_checksum(bc));
00829     else                        ffio_get_checksum(bc);
00830 
00831     avio_write(bc, pkt->data + nut->header_len[header_idx], pkt->size - nut->header_len[header_idx]);
00832     nus->last_flags= flags;
00833     nus->last_pts= pkt->pts;
00834 
00835     //FIXME just store one per syncpoint
00836     if(flags & FLAG_KEY)
00837         av_add_index_entry(
00838             s->streams[pkt->stream_index],
00839             nut->last_syncpoint_pos,
00840             pkt->pts,
00841             0,
00842             0,
00843             AVINDEX_KEYFRAME);
00844 
00845     return 0;
00846 }
00847 
00848 static int nut_write_trailer(AVFormatContext *s){
00849     NUTContext *nut= s->priv_data;
00850     AVIOContext *bc= s->pb;
00851 
00852     while(nut->header_count<3)
00853         write_headers(s, bc);
00854     avio_flush(bc);
00855     ff_nut_free_sp(nut);
00856     av_freep(&nut->stream);
00857     av_freep(&nut->chapter);
00858     av_freep(&nut->time_base);
00859 
00860     return 0;
00861 }
00862 
00863 AVOutputFormat ff_nut_muxer = {
00864     .name           = "nut",
00865     .long_name      = NULL_IF_CONFIG_SMALL("NUT format"),
00866     .mime_type      = "video/x-nut",
00867     .extensions     = "nut",
00868     .priv_data_size = sizeof(NUTContext),
00869 #if   CONFIG_LIBVORBIS
00870     .audio_codec    = CODEC_ID_VORBIS,
00871 #elif CONFIG_LIBMP3LAME
00872     .audio_codec    = CODEC_ID_MP3,
00873 #else
00874     .audio_codec    = CODEC_ID_MP2,
00875 #endif
00876     .video_codec    = CODEC_ID_MPEG4,
00877     .write_header   = nut_write_header,
00878     .write_packet   = nut_write_packet,
00879     .write_trailer  = nut_write_trailer,
00880     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
00881     .codec_tag = (const AVCodecTag * const []){ ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
00882 };
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