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     FrameCode *ft;
  34
  35     ft= &nut->frame_code[start];
  36     ft->flags= FLAG_CODED;
  37     ft->size_mul=1;
  38     ft->pts_delta=1;
  39     start++;
  40
  41     if(keyframe_0_esc){
  42         /* keyframe = 0 escape */
  43         FrameCode *ft= &nut->frame_code[start];
  44         ft->flags= FLAG_STREAM_ID | FLAG_SIZE_MSB | FLAG_CODED_PTS;
  45         ft->size_mul=1;
  46         start++;
  47     }
  48
  49     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){
  50         int start2= start + (end-start)*stream_id / s->nb_streams;
  51         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;
  52         AVCodecContext *codec = s->streams[stream_id]->codec;
  53         int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;
  54         int intra_only= /*codec->intra_only || */is_audio;
  55         int pred_count;
  56
  57         for(key_frame=0; key_frame<2; key_frame++){
  58             if(intra_only && keyframe_0_esc && key_frame==0)
  59                 continue;
  60
  61             {
  62                 FrameCode *ft= &nut->frame_code[start2];
  63                 ft->flags= FLAG_KEY*key_frame;
  64                 ft->flags|= FLAG_SIZE_MSB | FLAG_CODED_PTS;
  65                 ft->stream_id= stream_id;
  66                 ft->size_mul=1;
  67                 start2++;
  68             }
  69         }
  70
  71         key_frame= intra_only;
  72 #if 1
  73         if(is_audio){
  74             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);
  75             int pts;
  76             for(pts=0; pts<2; pts++){
  77                 for(pred=0; pred<2; pred++){
  78                     FrameCode *ft= &nut->frame_code[start2];
  79                     ft->flags= FLAG_KEY*key_frame;
  80                     ft->stream_id= stream_id;
  81                     ft->size_mul=frame_bytes + 2;
  82                     ft->size_lsb=frame_bytes + pred;
  83                     ft->pts_delta=pts;
  84                     start2++;
  85                 }
  86             }
  87         }else{
  88             FrameCode *ft= &nut->frame_code[start2];
  89             ft->flags= FLAG_KEY | FLAG_SIZE_MSB;
  90             ft->stream_id= stream_id;
  91             ft->size_mul=1;
  92             ft->pts_delta=1;
  93             start2++;
  94         }
  95 #endif
  96
  97         if(codec->has_b_frames){
  98             pred_count=5;
  99             pred_table[0]=-2;
 100             pred_table[1]=-1;
 101             pred_table[2]=1;
 102             pred_table[3]=3;
 103             pred_table[4]=4;
 104         }else if(codec->codec_id == CODEC_ID_VORBIS){
 105             pred_count=3;
 106             pred_table[0]=2;
 107             pred_table[1]=9;
 108             pred_table[2]=16;
 109         }else{
 110             pred_count=1;
 111             pred_table[0]=1;
 112         }
 113
 114         for(pred=0; pred<pred_count; pred++){
 115             int start3= start2 + (end2-start2)*pred / pred_count;
 116             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;
 117
 118             for(index=start3; index<end3; index++){
 119                 FrameCode *ft= &nut->frame_code[index];
 120                 ft->flags= FLAG_KEY*key_frame;
 121                 ft->flags|= FLAG_SIZE_MSB;
 122                 ft->stream_id= stream_id;
 123 //FIXME use single byte size and pred from last
 124                 ft->size_mul= end3-start3;
 125                 ft->size_lsb= index - start3;
 126                 ft->pts_delta= pred_table[pred];
 127             }
 128         }
 129     }
 130     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));
 131     nut->frame_code[  0].flags=
 132     nut->frame_code[255].flags=
 133     nut->frame_code['N'].flags= FLAG_INVALID;
 134 }
 135
 136 /**
 137  * Gets the length in bytes which is needed to store val as v.
 138  */
 139 static int get_length(uint64_t val){
 140     int i=1;
 141
 142     while(val>>=7)
 143         i++;
 144
 145     return i;
 146 }
 147
 148 static void put_v(ByteIOContext *bc, uint64_t val){
 149     int i= get_length(val);
 150
 151     while(--i>0)
 152         put_byte(bc, 128 | (val>>(7*i)));
 153
 154     put_byte(bc, val&127);
 155 }
 156
 157 /**
 158  * stores a string as vb.
 159  */
 160 static void put_str(ByteIOContext *bc, const char *string){
 161     int len= strlen(string);
 162
 163     put_v(bc, len);
 164     put_buffer(bc, string, len);
 165 }
 166
 167 static void put_s(ByteIOContext *bc, int64_t val){
 168     put_v(bc, 2*FFABS(val) - (val>0));
 169 }
 170
 171 #ifdef TRACE
 172 static inline void put_v_trace(ByteIOContext *bc, uint64_t v, char *file, char *func, int line){
 173     printf("get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 174
 175     put_v(bc, v);
 176 }
 177
 178 static inline void put_s_trace(ByteIOContext *bc, int64_t v, char *file, char *func, int line){
 179     printf("get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
 180
 181     put_s(bc, v);
 182 }
 183 #define put_v(bc, v)  put_v_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 184 #define put_s(bc, v)  put_s_trace(bc, v, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 185 #endif
 186
 187 static void put_packet(NUTContext *nut, ByteIOContext *bc, ByteIOContext *dyn_bc, int calculate_checksum){
 188     uint8_t *dyn_buf=NULL;
 189     int dyn_size= url_close_dyn_buf(dyn_bc, &dyn_buf);
 190     int forw_ptr= dyn_size + 4*calculate_checksum;
 191
 192     if(forw_ptr > 4096)
 193         init_checksum(bc, av_crc04C11DB7_update, 0);
 194     put_v(bc, forw_ptr);
 195     if(forw_ptr > 4096)
 196         put_le32(bc, get_checksum(bc));
 197
 198     if(calculate_checksum)
 199         init_checksum(bc, av_crc04C11DB7_update, 0);
 200     put_buffer(bc, dyn_buf, dyn_size);
 201     if(calculate_checksum)
 202         put_le32(bc, get_checksum(bc));
 203
 204     av_free(dyn_buf);
 205 }
 206
 207 static void write_mainheader(NUTContext *nut, ByteIOContext *bc){
 208     int i, j, tmp_pts, tmp_flags, tmp_stream, tmp_mul, tmp_size, tmp_fields;
 209
 210     put_v(bc, 2); /* version */
 211     put_v(bc, nut->avf->nb_streams);
 212     put_v(bc, MAX_DISTANCE);
 213     put_v(bc, nut->time_base_count);
 214
 215     for(i=0; i<nut->time_base_count; i++){
 216         put_v(bc, nut->time_base[i].num);
 217         put_v(bc, nut->time_base[i].den);
 218     }
 219
 220     tmp_pts=0;
 221     tmp_mul=1;
 222     tmp_stream=0;
 223     for(i=0; i<256;){
 224         tmp_fields=0;
 225         tmp_size=0;
 226 //        tmp_res=0;
 227         if(tmp_pts    != nut->frame_code[i].pts_delta) tmp_fields=1;
 228         if(tmp_mul    != nut->frame_code[i].size_mul ) tmp_fields=2;
 229         if(tmp_stream != nut->frame_code[i].stream_id) tmp_fields=3;
 230         if(tmp_size   != nut->frame_code[i].size_lsb ) tmp_fields=4;
 231 //        if(tmp_res    != nut->frame_code[i].res            ) tmp_fields=5;
 232
 233         tmp_pts   = nut->frame_code[i].pts_delta;
 234         tmp_flags = nut->frame_code[i].flags;
 235         tmp_stream= nut->frame_code[i].stream_id;
 236         tmp_mul   = nut->frame_code[i].size_mul;
 237         tmp_size  = nut->frame_code[i].size_lsb;
 238 //        tmp_res   = nut->frame_code[i].res;
 239
 240         for(j=0; i<256; j++,i++){
 241             if(i == 'N'){
 242                 j--;
 243                 continue;
 244             }
 245             if(nut->frame_code[i].pts_delta != tmp_pts   ) break;
 246             if(nut->frame_code[i].flags     != tmp_flags ) break;
 247             if(nut->frame_code[i].stream_id != tmp_stream) break;
 248             if(nut->frame_code[i].size_mul  != tmp_mul   ) break;
 249             if(nut->frame_code[i].size_lsb  != tmp_size+j) break;
 250 //            if(nut->frame_code[i].res       != tmp_res   ) break;
 251         }
 252         if(j != tmp_mul - tmp_size) tmp_fields=6;
 253
 254         put_v(bc, tmp_flags);
 255         put_v(bc, tmp_fields);
 256         if(tmp_fields>0) put_s(bc, tmp_pts);
 257         if(tmp_fields>1) put_v(bc, tmp_mul);
 258         if(tmp_fields>2) put_v(bc, tmp_stream);
 259         if(tmp_fields>3) put_v(bc, tmp_size);
 260         if(tmp_fields>4) put_v(bc, 0 /*tmp_res*/);
 261         if(tmp_fields>5) put_v(bc, j);
 262     }
 263 }
 264
 265 static int write_streamheader(NUTContext *nut, ByteIOContext *bc, AVCodecContext *codec, int i){
 266     put_v(bc, i);
 267     switch(codec->codec_type){
 268     case CODEC_TYPE_VIDEO: put_v(bc, 0); break;
 269     case CODEC_TYPE_AUDIO: put_v(bc, 1); break;
 270 //    case CODEC_TYPE_TEXT : put_v(bc, 2); break;
 271     default              : put_v(bc, 3); break;
 272     }
 273     put_v(bc, 4);
 274     if (codec->codec_tag){
 275         put_le32(bc, codec->codec_tag);
 276     }else
 277         return -1;
 278
 279     put_v(bc, (nut->stream[i].time_base - nut->time_base)/sizeof(AVRational));
 280     put_v(bc, nut->stream[i].msb_pts_shift);
 281     put_v(bc, nut->stream[i].max_pts_distance);
 282     put_v(bc, codec->has_b_frames);
 283     put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */
 284
 285     put_v(bc, codec->extradata_size);
 286     put_buffer(bc, codec->extradata, codec->extradata_size);
 287
 288     switch(codec->codec_type){
 289     case CODEC_TYPE_AUDIO:
 290         put_v(bc, codec->sample_rate);
 291         put_v(bc, 1);
 292         put_v(bc, codec->channels);
 293         break;
 294     case CODEC_TYPE_VIDEO:
 295         put_v(bc, codec->width);
 296         put_v(bc, codec->height);
 297         put_v(bc, codec->sample_aspect_ratio.num);
 298         put_v(bc, codec->sample_aspect_ratio.den);
 299         put_v(bc, 0); /* csp type -- unknown */
 300         break;
 301     default:
 302         break;
 303     }
 304     return 0;
 305 }
 306
 307 static int write_header(AVFormatContext *s){
 308     NUTContext *nut = s->priv_data;
 309     ByteIOContext *bc = &s->pb, dyn_bc;
 310     AVCodecContext *codec;
 311     int i, j;
 312
 313     nut->avf= s;
 314
 315     nut->stream   = av_mallocz(sizeof(StreamContext)*s->nb_streams);
 316     nut->time_base= av_mallocz(sizeof(AVRational   )*s->nb_streams);
 317
 318     for(i=0; i<s->nb_streams; i++){
 319         AVStream *st= s->streams[i];
 320         int ssize;
 321         AVRational time_base;
 322         ff_parse_specific_params(st->codec, &time_base.den, &ssize, &time_base.num);
 323
 324         av_set_pts_info(st, 64, time_base.num, time_base.den);
 325
 326         for(j=0; j<nut->time_base_count; j++){
 327             if(!memcmp(&time_base, &nut->time_base[j], sizeof(AVRational))){
 328                 break;
 329             }
 330         }
 331         nut->time_base[j]= time_base;
 332         nut->stream[i].time_base= &nut->time_base[j];
 333         if(j==nut->time_base_count)
 334             nut->time_base_count++;
 335
 336         if(av_q2d(time_base) >= 0.001)
 337             nut->stream[i].msb_pts_shift = 7;
 338         else
 339             nut->stream[i].msb_pts_shift = 14;
 340         nut->stream[i].max_pts_distance= FFMAX(1/av_q2d(time_base), 1);
 341     }
 342
 343     build_frame_code(s);
 344     assert(nut->frame_code['N'].flags == FLAG_INVALID);
 345
 346     put_buffer(bc, ID_STRING, strlen(ID_STRING));
 347     put_byte(bc, 0);
 348
 349     /* main header */
 350     put_be64(bc, MAIN_STARTCODE);
 351     url_open_dyn_buf(&dyn_bc);
 352     write_mainheader(nut, &dyn_bc);
 353     put_packet(nut, bc, &dyn_bc, 1);
 354
 355     for (i=0; i < s->nb_streams; i++){
 356         codec = s->streams[i]->codec;
 357
 358         put_be64(bc, STREAM_STARTCODE);
 359         url_open_dyn_buf(&dyn_bc);
 360         write_streamheader(nut, &dyn_bc, codec, i);
 361         put_packet(nut, bc, &dyn_bc, 1);
 362     }
 363
 364     put_flush_packet(bc);
 365
 366     //FIXME info header, header repeation, ...
 367
 368     return 0;
 369 }
 370
 371 static int write_packet(AVFormatContext *s, AVPacket *pkt){
 372     //FIXME
 373     return 0;
 374 }
 375
 376 AVOutputFormat nut_muxer = {
 377     "nut",
 378     "nut format",
 379     "video/x-nut",
 380     "nut",
 381     sizeof(NUTContext),
 382 #ifdef CONFIG_LIBVORBIS
 383     CODEC_ID_VORBIS,
 384 #elif defined(CONFIG_LIBMP3LAME)
 385     CODEC_ID_MP3,
 386 #else
 387     CODEC_ID_MP2, /* AC3 needs liba52 decoder */
 388 #endif
 389     CODEC_ID_MPEG4,
 390     write_header,
 391     write_packet,
 392 //    write_trailer,
 393     .flags = AVFMT_GLOBALHEADER,
 394     .codec_tag= (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},
 395 };