git.sesse.net Git - ffmpeg/blob - libavformat/nutenc.c

   1 /*
   2  * nut muxer
   3  * Copyright (c) 2004-2007 Michael Niedermayer
   4  *
   5  * This file is part of FFmpeg.
   6  *
   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.
  11  *
  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.
  16  *
  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
  20  */
  21
  22 #include "nut.h"
  23
  24 #define TRACE
  25
  26 static void build_frame_code(AVFormatContext *s){
  27     NUTContext *nut = s->priv_data;
  28     int key_frame, index, pred, stream_id;
  29     int start=1;
  30     int end= 254;
  31     int keyframe_0_esc= s->nb_streams > 2;
  32     int pred_table[10];
  33
  34     if(keyframe_0_esc){
  35         /* keyframe = 0 escape */
  36         FrameCode *ft= &nut->frame_code[start];
  37         ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
  38         ft->size_mul=1;
  39         start++;
  40     }
  41
  42     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
  43         int start2= start + (end-start)*stream_id / s->nb_streams;
  44         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
  45         AVCodecContext *codec = s->streams[stream_id]->codec;
  46         int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
  47         int intra_only= /*codec->intra_only || */is_audio;
  48         int pred_count;
  49
  50         for(key_frame=0; key_frame<2; key_frame++){
  51             if(intra_only && keyframe_0_esc && key_frame==0)
  52                 continue;
  53
  54             {
  55                 FrameCode *ft= &nut->frame_code[start2];
  56                 ft->flags= FLAG_KEY*key_frame;
  57                 ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
  58                 ft->stream_id= stream_id;
  59                 ft->size_mul=1;
  60                 start2++;
  61             }
  62         }
  63
  64         key_frame= intra_only;
  65 #if 1
  66         if(is_audio){
  67             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
  68             int pts;
  69             for(pts=0; pts<2; pts++){
  70                 for(pred=0; pred<2; pred++){
  71                     FrameCode *ft= &nut->frame_code[start2];
  72                     ft->flags= FLAG_KEY*key_frame;
  73                     ft->stream_id= stream_id;
  74                     ft->size_mul=frame_bytes + 2;
  75                     ft->size_lsb=frame_bytes + pred;
  76                     ft->pts_delta=pts;
  77                     start2++;
  78                 }
  79             }
  80         }else{
  81             FrameCode *ft= &nut->frame_code[start2];
  82             ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
  83             ft->stream_id= stream_id;
  84             ft->size_mul=1;
  85             ft->pts_delta=1;
  86             start2++;
  87         }
  88 #endif
  89
  90         if(codec->has_b_frames){
  91             pred_count=5;
  92             pred_table[0]=-2;
  93             pred_table[1]=-1;
  94             pred_table[2]=1;
  95             pred_table[3]=3;
  96             pred_table[4]=4;
  97         }else if(codec->codec_id == CODEC_ID_VORBIS){
  98             pred_count=3;
  99             pred_table[0]=2;
 100             pred_table[1]=9;
 101             pred_table[2]=16;
 102         }else{
 103             pred_count=1;
 104             pred_table[0]=1;
 105         }
 106
 107         for(pred=0; pred<pred_count; pred++){
 108             int start3= start2 + (end2-start2)*pred / pred_count;
 109             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
 110
 111             for(index=start3; index<end3; index++){
 112                 FrameCode *ft= &nut->frame_code[index];
 113                 ft->flags= FLAG_KEY*key_frame;
 114                 ft->flags|= FLAG_SIZE_MSB;
 115                 ft->stream_id= stream_id;
 116 //FIXME use single byte size and pred from last
 117                 ft->size_mul= end3-start3;
 118                 ft->size_lsb= index - start3;
 119                 ft->pts_delta= pred_table[pred];
 120             }
 121         }
 122     }
 123     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
 124     nut->frame_code[  0].flags=
 125     nut->frame_code[255].flags=
 126     nut->frame_code['N'].flags= FLAG_INVALID;
 127 }
 128
 129 /**
 130  * Gets the length in bytes which is needed to store val as v.
 131  */
 132 static int get_length(uint64_t val){
 133     int i=1;
 134
 135     while(val>>=7)
 136         i++;
 137
 138     return i;
 139 }
 140
 141 static void put_v(ByteIOContext *bc, uint64_t val){
 142     int i= get_length(val);
 143
 144     while(--i>0)
 145         put_byte(bc, 128 | (val>>(7*i)));
 146
 147     put_byte(bc, val&127);
 148 }
 149
 150 /**
 151  * stores a string as vb.
 152  */
 153 static void put_str(ByteIOContext *bc, const char *string){
 154     int len= strlen(string);
 155
 156     put_v(bc, len);
 157     put_buffer(bc, string, len);
 158 }
 159
 160 static void put_s(ByteIOContext *bc, int64_t val){
 161     put_v(bc, 2*FFABS(val) - (val>0));
 162 }
 163
 164 #ifdef TRACE
 165 static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
 166     printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 167
 168     put_v(bc, v);
 169 }
 170
 171 static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
 172     printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 173
 174     put_s(bc, v);
 175 }
 176 #define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 177 #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 178 #endif
 179
 180 static int put_packetheader(NUTContext *nut, ByteIOContext *bc, int max_size, int calculate_checksum){
 181     put_flush_packet(bc);
 182     nut->packet_start= url_ftell(bc) - 8;
 183     nut->written_packet_size = max_size;
 184
 185     /* packet header */
 186     put_v(bc, nut->written_packet_size); /* forward ptr */
 187
 188     if(calculate_checksum)
 189         init_checksum(bc, av_crc04C11DB7_update, 0);
 190
 191     return 0;
 192 }
 193
 194 /**
 195  *
 196  * must not be called more then once per packet
 197  */
 198 static int update_packetheader(NUTContext *nut, ByteIOContext *bc, int additional_size, int calculate_checksum){
 199     int64_t start= nut->packet_start;
 200     int64_t cur= url_ftell(bc);
 201     int size= cur - start - get_length(nut->written_packet_size) - 8;
 202
 203     if(calculate_checksum)
 204         size += 4;
 205
 206     if(size != nut->written_packet_size){
 207         int i;
 208
 209         assert( size <= nut->written_packet_size );
 210
 211         url_fseek(bc, start + 8, SEEK_SET);
 212         for(i=get_length(size); i < get_length(nut->written_packet_size); i++)
 213             put_byte(bc, 128);
 214         put_v(bc, size);
 215
 216         url_fseek(bc, cur, SEEK_SET);
 217         nut->written_packet_size= size; //FIXME may fail if multiple updates with differing sizes, as get_length may differ
 218
 219         if(calculate_checksum)
 220             put_le32(bc, get_checksum(bc));
 221     }
 222
 223     return 0;
 224 }
 225
 226 static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
 227     int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields;
 228
 229     put_v(bc, 2); /* version */
 230     put_v(bc, nut->avf->nb_streams);
 231     put_v(bc, MAX_DISTANCE);
 232     put_v(bc, nut->time_base_count);
 233
 234     for(i=0; i<nut->time_base_count; i++){
 235         put_v(bc, nut->time_base[i].num);
 236         put_v(bc, nut->time_base[i].den);
 237     }
 238
 239     tmp_pts=0;
 240     tmp_mul=1;
 241     tmp_stream=0;
 242     for(i=0; i<256;){
 243         tmp_fields=0;
 244         tmp_size=0;
 245 //        tmp_res=0;
 246         if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
 247         if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
 248         if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
 249         if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
 250 //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
 251
 252         tmp_pts   = nut->frame_code[i].pts_delta;
 253         tmp_flags = nut->frame_code[i].flags;
 254         tmp_stream= nut->frame_code[i].stream_id;
 255         tmp_mul   = nut->frame_code[i].size_mul;
 256         tmp_size  = nut->frame_code[i].size_lsb;
 257 //        tmp_res   = nut->frame_code[i].res;
 258
 259         for(j=0; i<256; j++,i++){
 260             if(i == 'N'){
 261                 j--;
 262                 continue;
 263             }
 264             if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
 265             if(nut->frame_code[i].flags     != tmp_flags ) break;
 266             if(nut->frame_code[i].stream_id != tmp_stream) break;
 267             if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
 268             if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
 269 //            if(nut->frame_code[i].res       != tmp_res   ) break;
 270         }
 271         if(j != tmp_mul - tmp_size) tmp_fields=6;
 272
 273         put_v(bc, tmp_flags);
 274         put_v(bc, tmp_fields);
 275         if(tmp_fields>0) put_s(bc, tmp_pts);
 276         if(tmp_fields>1) put_v(bc, tmp_mul);
 277         if(tmp_fields>2) put_v(bc, tmp_stream);
 278         if(tmp_fields>3) put_v(bc, tmp_size);
 279         if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
 280         if(tmp_fields>5) put_v(bc, j);
 281     }
 282 }
 283
 284 static int write_header(AVFormatContext *s){
 285     NUTContext *nut = s->priv_data;
 286     ByteIOContext *bc = &s->pb;
 287     AVCodecContext *codec;
 288     int i, j;
 289
 290     nut->avf= s;
 291
 292     nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
 293     nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
 294
 295     for(i=0; i<s->nb_streams; i++){
 296         AVStream *st= s->streams[i];
 297         int ssize;
 298         AVRational time_base;
 299         ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
 300
 301         av_set_pts_info(st, 64, time_base.num, time_base.den);
 302
 303         for(j=0; j<nut->time_base_count; j++){
 304             if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
 305                 break;
 306             }
 307         }
 308         nut->time_base[j]= time_base;
 309         nut->stream[i].time_base= &nut->time_base[j];
 310         if(j==nut->time_base_count)
 311             nut->time_base_count++;
 312
 313         if(av_q2d(time_base) >= 0.001)
 314             nut->stream[i].msb_pts_shift = 7;
 315         else
 316             nut->stream[i].msb_pts_shift = 14;
 317         nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
 318     }
 319
 320     build_frame_code(s);
 321     assert(nut->frame_code['N'].flags == FLAG_INVALID);
 322
 323     put_buffer(bc, ID_STRING, strlen(ID_STRING));
 324     put_byte(bc, 0);
 325
 326     /* main header */
 327     put_be64(bc, MAIN_STARTCODE);
 328     put_packetheader(nut, bc, 120+5*256/*FIXME check*/, 1);
 329     write_mainheader(nut, bc);
 330     update_packetheader(nut, bc, 0, 1);
 331
 332     for (i=0; i < s->nb_streams; i++){
 333         codec = s->streams[i]->codec;
 334
 335         put_be64(bc, STREAM_STARTCODE);
 336         put_packetheader(nut, bc, 120/*FIXME check*/ + codec->extradata_size, 1);
 337         put_v(bc, i);
 338         switch(codec->codec_type){
 339         case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
 340         case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
 341 //        case CODEC_TYPE_TEXT : put_v(bc, 2); break;
 342         default              : put_v(bc, 3); break;
 343         }
 344         put_v(bc, 4);
 345         if (codec->codec_tag){
 346             put_le32(bc, codec->codec_tag);
 347         }else
 348             return -1;
 349
 350         put_v(bc, (nut->stream[i].time_base - nut->time_base)/sizeof(AVRational));
 351         put_v(bc, nut->stream[i].msb_pts_shift);
 352         put_v(bc, nut->stream[i].max_pts_distance);
 353         put_v(bc, codec->has_b_frames);
 354         put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
 355
 356         put_v(bc, codec->extradata_size);
 357         put_buffer(bc, codec->extradata, codec->extradata_size);
 358
 359         switch(codec->codec_type){
 360         case CODEC_TYPE_AUDIO:
 361             put_v(bc, codec->sample_rate);
 362             put_v(bc, 1);
 363             put_v(bc, codec->channels);
 364             break;
 365         case CODEC_TYPE_VIDEO:
 366             put_v(bc, codec->width);
 367             put_v(bc, codec->height);
 368             put_v(bc, codec->sample_aspect_ratio.num);
 369             put_v(bc, codec->sample_aspect_ratio.den);
 370             put_v(bc, 0); /* csp type -- unknown */
 371             break;
 372         default:
 373             break;
 374         }
 375         update_packetheader(nut, bc, 0, 1);
 376     }
 377
 378     put_flush_packet(bc);
 379
 380     //FIXME info header, header repeation, header packet CRC, ...
 381
 382     return 0;
 383 }
 384
 385 static int write_packet(AVFormatContext *s, AVPacket *pkt){
 386     //FIXME
 387     return 0;
 388 }
 389
 390 AVOutputFormat nut_muxer = {
 391     "nut",
 392     "nut format",
 393     "video/x-nut",
 394     "nut",
 395     sizeof(NUTContext),
 396 #ifdef CONFIG_LIBVORBIS
 397     CODEC_ID_VORBIS,
 398 #elif defined(CONFIG_LIBMP3LAME)
 399     CODEC_ID_MP3,
 400 #else
 401     CODEC_ID_MP2, /* AC3 needs liba52 decoder */
 402 #endif
 403     CODEC_ID_MPEG4,
 404     write_header,
 405     write_packet,
 406 //    write_trailer,
 407     .flags = AVFMT_GLOBALHEADER,
 408     .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
 409 };