• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavcodec/mjpegenc.c

Go to the documentation of this file.
00001 /*
00002  * MJPEG encoder
00003  * Copyright (c) 2000, 2001 Fabrice Bellard
00004  * Copyright (c) 2003 Alex Beregszaszi
00005  * Copyright (c) 2003-2004 Michael Niedermayer
00006  *
00007  * Support for external huffman table, various fixes (AVID workaround),
00008  * aspecting, new decode_frame mechanism and apple mjpeg-b support
00009  *                                  by Alex Beregszaszi
00010  *
00011  * This file is part of FFmpeg.
00012  *
00013  * FFmpeg is free software; you can redistribute it and/or
00014  * modify it under the terms of the GNU Lesser General Public
00015  * License as published by the Free Software Foundation; either
00016  * version 2.1 of the License, or (at your option) any later version.
00017  *
00018  * FFmpeg is distributed in the hope that it will be useful,
00019  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00020  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00021  * Lesser General Public License for more details.
00022  *
00023  * You should have received a copy of the GNU Lesser General Public
00024  * License along with FFmpeg; if not, write to the Free Software
00025  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00026  */
00027 
00033 //#define DEBUG
00034 #include <assert.h>
00035 
00036 #include "avcodec.h"
00037 #include "dsputil.h"
00038 #include "mpegvideo.h"
00039 #include "mjpeg.h"
00040 #include "mjpegenc.h"
00041 
00042 /* use two quantizer tables (one for luminance and one for chrominance) */
00043 /* not yet working */
00044 #undef TWOMATRIXES
00045 
00046 
00047 av_cold int ff_mjpeg_encode_init(MpegEncContext *s)
00048 {
00049     MJpegContext *m;
00050 
00051     m = av_malloc(sizeof(MJpegContext));
00052     if (!m)
00053         return -1;
00054 
00055     s->min_qcoeff=-1023;
00056     s->max_qcoeff= 1023;
00057 
00058     /* build all the huffman tables */
00059     ff_mjpeg_build_huffman_codes(m->huff_size_dc_luminance,
00060                                  m->huff_code_dc_luminance,
00061                                  ff_mjpeg_bits_dc_luminance,
00062                                  ff_mjpeg_val_dc);
00063     ff_mjpeg_build_huffman_codes(m->huff_size_dc_chrominance,
00064                                  m->huff_code_dc_chrominance,
00065                                  ff_mjpeg_bits_dc_chrominance,
00066                                  ff_mjpeg_val_dc);
00067     ff_mjpeg_build_huffman_codes(m->huff_size_ac_luminance,
00068                                  m->huff_code_ac_luminance,
00069                                  ff_mjpeg_bits_ac_luminance,
00070                                  ff_mjpeg_val_ac_luminance);
00071     ff_mjpeg_build_huffman_codes(m->huff_size_ac_chrominance,
00072                                  m->huff_code_ac_chrominance,
00073                                  ff_mjpeg_bits_ac_chrominance,
00074                                  ff_mjpeg_val_ac_chrominance);
00075 
00076     s->mjpeg_ctx = m;
00077     return 0;
00078 }
00079 
00080 void ff_mjpeg_encode_close(MpegEncContext *s)
00081 {
00082     av_free(s->mjpeg_ctx);
00083 }
00084 
00085 /* table_class: 0 = DC coef, 1 = AC coefs */
00086 static int put_huffman_table(MpegEncContext *s, int table_class, int table_id,
00087                              const uint8_t *bits_table, const uint8_t *value_table)
00088 {
00089     PutBitContext *p = &s->pb;
00090     int n, i;
00091 
00092     put_bits(p, 4, table_class);
00093     put_bits(p, 4, table_id);
00094 
00095     n = 0;
00096     for(i=1;i<=16;i++) {
00097         n += bits_table[i];
00098         put_bits(p, 8, bits_table[i]);
00099     }
00100 
00101     for(i=0;i<n;i++)
00102         put_bits(p, 8, value_table[i]);
00103 
00104     return n + 17;
00105 }
00106 
00107 static void jpeg_table_header(MpegEncContext *s)
00108 {
00109     PutBitContext *p = &s->pb;
00110     int i, j, size;
00111     uint8_t *ptr;
00112 
00113     /* quant matrixes */
00114     put_marker(p, DQT);
00115 #ifdef TWOMATRIXES
00116     put_bits(p, 16, 2 + 2 * (1 + 64));
00117 #else
00118     put_bits(p, 16, 2 + 1 * (1 + 64));
00119 #endif
00120     put_bits(p, 4, 0); /* 8 bit precision */
00121     put_bits(p, 4, 0); /* table 0 */
00122     for(i=0;i<64;i++) {
00123         j = s->intra_scantable.permutated[i];
00124         put_bits(p, 8, s->intra_matrix[j]);
00125     }
00126 #ifdef TWOMATRIXES
00127     put_bits(p, 4, 0); /* 8 bit precision */
00128     put_bits(p, 4, 1); /* table 1 */
00129     for(i=0;i<64;i++) {
00130         j = s->intra_scantable.permutated[i];
00131         put_bits(p, 8, s->chroma_intra_matrix[j]);
00132     }
00133 #endif
00134 
00135     /* huffman table */
00136     put_marker(p, DHT);
00137     flush_put_bits(p);
00138     ptr = put_bits_ptr(p);
00139     put_bits(p, 16, 0); /* patched later */
00140     size = 2;
00141     size += put_huffman_table(s, 0, 0, ff_mjpeg_bits_dc_luminance,
00142                               ff_mjpeg_val_dc);
00143     size += put_huffman_table(s, 0, 1, ff_mjpeg_bits_dc_chrominance,
00144                               ff_mjpeg_val_dc);
00145 
00146     size += put_huffman_table(s, 1, 0, ff_mjpeg_bits_ac_luminance,
00147                               ff_mjpeg_val_ac_luminance);
00148     size += put_huffman_table(s, 1, 1, ff_mjpeg_bits_ac_chrominance,
00149                               ff_mjpeg_val_ac_chrominance);
00150     AV_WB16(ptr, size);
00151 }
00152 
00153 static void jpeg_put_comments(MpegEncContext *s)
00154 {
00155     PutBitContext *p = &s->pb;
00156     int size;
00157     uint8_t *ptr;
00158 
00159     if (s->avctx->sample_aspect_ratio.num /* && !lossless */)
00160     {
00161     /* JFIF header */
00162     put_marker(p, APP0);
00163     put_bits(p, 16, 16);
00164     ff_put_string(p, "JFIF", 1); /* this puts the trailing zero-byte too */
00165     put_bits(p, 16, 0x0102); /* v 1.02 */
00166     put_bits(p, 8, 0); /* units type: 0 - aspect ratio */
00167     put_bits(p, 16, s->avctx->sample_aspect_ratio.num);
00168     put_bits(p, 16, s->avctx->sample_aspect_ratio.den);
00169     put_bits(p, 8, 0); /* thumbnail width */
00170     put_bits(p, 8, 0); /* thumbnail height */
00171     }
00172 
00173     /* comment */
00174     if(!(s->flags & CODEC_FLAG_BITEXACT)){
00175         put_marker(p, COM);
00176         flush_put_bits(p);
00177         ptr = put_bits_ptr(p);
00178         put_bits(p, 16, 0); /* patched later */
00179         ff_put_string(p, LIBAVCODEC_IDENT, 1);
00180         size = strlen(LIBAVCODEC_IDENT)+3;
00181         AV_WB16(ptr, size);
00182     }
00183 
00184     if(  s->avctx->pix_fmt == PIX_FMT_YUV420P
00185        ||s->avctx->pix_fmt == PIX_FMT_YUV422P
00186        ||s->avctx->pix_fmt == PIX_FMT_YUV444P){
00187         put_marker(p, COM);
00188         flush_put_bits(p);
00189         ptr = put_bits_ptr(p);
00190         put_bits(p, 16, 0); /* patched later */
00191         ff_put_string(p, "CS=ITU601", 1);
00192         size = strlen("CS=ITU601")+3;
00193         AV_WB16(ptr, size);
00194     }
00195 }
00196 
00197 void ff_mjpeg_encode_picture_header(MpegEncContext *s)
00198 {
00199     const int lossless= s->avctx->codec_id != CODEC_ID_MJPEG;
00200 
00201     put_marker(&s->pb, SOI);
00202 
00203     // hack for AMV mjpeg format
00204     if(s->avctx->codec_id == CODEC_ID_AMV) return;
00205 
00206     jpeg_put_comments(s);
00207 
00208     jpeg_table_header(s);
00209 
00210     switch(s->avctx->codec_id){
00211     case CODEC_ID_MJPEG:  put_marker(&s->pb, SOF0 ); break;
00212     case CODEC_ID_LJPEG:  put_marker(&s->pb, SOF3 ); break;
00213     default: assert(0);
00214     }
00215 
00216     put_bits(&s->pb, 16, 17);
00217     if(lossless && s->avctx->pix_fmt == PIX_FMT_BGRA)
00218         put_bits(&s->pb, 8, 9); /* 9 bits/component RCT */
00219     else
00220         put_bits(&s->pb, 8, 8); /* 8 bits/component */
00221     put_bits(&s->pb, 16, s->height);
00222     put_bits(&s->pb, 16, s->width);
00223     put_bits(&s->pb, 8, 3); /* 3 components */
00224 
00225     /* Y component */
00226     put_bits(&s->pb, 8, 1); /* component number */
00227     put_bits(&s->pb, 4, s->mjpeg_hsample[0]); /* H factor */
00228     put_bits(&s->pb, 4, s->mjpeg_vsample[0]); /* V factor */
00229     put_bits(&s->pb, 8, 0); /* select matrix */
00230 
00231     /* Cb component */
00232     put_bits(&s->pb, 8, 2); /* component number */
00233     put_bits(&s->pb, 4, s->mjpeg_hsample[1]); /* H factor */
00234     put_bits(&s->pb, 4, s->mjpeg_vsample[1]); /* V factor */
00235 #ifdef TWOMATRIXES
00236     put_bits(&s->pb, 8, lossless ? 0 : 1); /* select matrix */
00237 #else
00238     put_bits(&s->pb, 8, 0); /* select matrix */
00239 #endif
00240 
00241     /* Cr component */
00242     put_bits(&s->pb, 8, 3); /* component number */
00243     put_bits(&s->pb, 4, s->mjpeg_hsample[2]); /* H factor */
00244     put_bits(&s->pb, 4, s->mjpeg_vsample[2]); /* V factor */
00245 #ifdef TWOMATRIXES
00246     put_bits(&s->pb, 8, lossless ? 0 : 1); /* select matrix */
00247 #else
00248     put_bits(&s->pb, 8, 0); /* select matrix */
00249 #endif
00250 
00251     /* scan header */
00252     put_marker(&s->pb, SOS);
00253     put_bits(&s->pb, 16, 12); /* length */
00254     put_bits(&s->pb, 8, 3); /* 3 components */
00255 
00256     /* Y component */
00257     put_bits(&s->pb, 8, 1); /* index */
00258     put_bits(&s->pb, 4, 0); /* DC huffman table index */
00259     put_bits(&s->pb, 4, 0); /* AC huffman table index */
00260 
00261     /* Cb component */
00262     put_bits(&s->pb, 8, 2); /* index */
00263     put_bits(&s->pb, 4, 1); /* DC huffman table index */
00264     put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */
00265 
00266     /* Cr component */
00267     put_bits(&s->pb, 8, 3); /* index */
00268     put_bits(&s->pb, 4, 1); /* DC huffman table index */
00269     put_bits(&s->pb, 4, lossless ? 0 : 1); /* AC huffman table index */
00270 
00271     put_bits(&s->pb, 8, lossless ? s->avctx->prediction_method+1 : 0); /* Ss (not used) */
00272 
00273     switch(s->avctx->codec_id){
00274     case CODEC_ID_MJPEG:  put_bits(&s->pb, 8, 63); break; /* Se (not used) */
00275     case CODEC_ID_LJPEG:  put_bits(&s->pb, 8,  0); break; /* not used */
00276     default: assert(0);
00277     }
00278 
00279     put_bits(&s->pb, 8, 0); /* Ah/Al (not used) */
00280 }
00281 
00282 static void escape_FF(MpegEncContext *s, int start)
00283 {
00284     int size= put_bits_count(&s->pb) - start*8;
00285     int i, ff_count;
00286     uint8_t *buf= s->pb.buf + start;
00287     int align= (-(size_t)(buf))&3;
00288 
00289     assert((size&7) == 0);
00290     size >>= 3;
00291 
00292     ff_count=0;
00293     for(i=0; i<size && i<align; i++){
00294         if(buf[i]==0xFF) ff_count++;
00295     }
00296     for(; i<size-15; i+=16){
00297         int acc, v;
00298 
00299         v= *(uint32_t*)(&buf[i]);
00300         acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
00301         v= *(uint32_t*)(&buf[i+4]);
00302         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
00303         v= *(uint32_t*)(&buf[i+8]);
00304         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
00305         v= *(uint32_t*)(&buf[i+12]);
00306         acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
00307 
00308         acc>>=4;
00309         acc+= (acc>>16);
00310         acc+= (acc>>8);
00311         ff_count+= acc&0xFF;
00312     }
00313     for(; i<size; i++){
00314         if(buf[i]==0xFF) ff_count++;
00315     }
00316 
00317     if(ff_count==0) return;
00318 
00319     flush_put_bits(&s->pb);
00320     skip_put_bytes(&s->pb, ff_count);
00321 
00322     for(i=size-1; ff_count; i--){
00323         int v= buf[i];
00324 
00325         if(v==0xFF){
00326 //printf("%d %d\n", i, ff_count);
00327             buf[i+ff_count]= 0;
00328             ff_count--;
00329         }
00330 
00331         buf[i+ff_count]= v;
00332     }
00333 }
00334 
00335 void ff_mjpeg_encode_stuffing(PutBitContext * pbc)
00336 {
00337     int length;
00338     length= (-put_bits_count(pbc))&7;
00339     if(length) put_bits(pbc, length, (1<<length)-1);
00340 }
00341 
00342 void ff_mjpeg_encode_picture_trailer(MpegEncContext *s)
00343 {
00344     ff_mjpeg_encode_stuffing(&s->pb);
00345     flush_put_bits(&s->pb);
00346 
00347     assert((s->header_bits&7)==0);
00348 
00349     escape_FF(s, s->header_bits>>3);
00350 
00351     put_marker(&s->pb, EOI);
00352 }
00353 
00354 void ff_mjpeg_encode_dc(MpegEncContext *s, int val,
00355                         uint8_t *huff_size, uint16_t *huff_code)
00356 {
00357     int mant, nbits;
00358 
00359     if (val == 0) {
00360         put_bits(&s->pb, huff_size[0], huff_code[0]);
00361     } else {
00362         mant = val;
00363         if (val < 0) {
00364             val = -val;
00365             mant--;
00366         }
00367 
00368         nbits= av_log2_16bit(val) + 1;
00369 
00370         put_bits(&s->pb, huff_size[nbits], huff_code[nbits]);
00371 
00372         put_sbits(&s->pb, nbits, mant);
00373     }
00374 }
00375 
00376 static void encode_block(MpegEncContext *s, DCTELEM *block, int n)
00377 {
00378     int mant, nbits, code, i, j;
00379     int component, dc, run, last_index, val;
00380     MJpegContext *m = s->mjpeg_ctx;
00381     uint8_t *huff_size_ac;
00382     uint16_t *huff_code_ac;
00383 
00384     /* DC coef */
00385     component = (n <= 3 ? 0 : (n&1) + 1);
00386     dc = block[0]; /* overflow is impossible */
00387     val = dc - s->last_dc[component];
00388     if (n < 4) {
00389         ff_mjpeg_encode_dc(s, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
00390         huff_size_ac = m->huff_size_ac_luminance;
00391         huff_code_ac = m->huff_code_ac_luminance;
00392     } else {
00393         ff_mjpeg_encode_dc(s, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
00394         huff_size_ac = m->huff_size_ac_chrominance;
00395         huff_code_ac = m->huff_code_ac_chrominance;
00396     }
00397     s->last_dc[component] = dc;
00398 
00399     /* AC coefs */
00400 
00401     run = 0;
00402     last_index = s->block_last_index[n];
00403     for(i=1;i<=last_index;i++) {
00404         j = s->intra_scantable.permutated[i];
00405         val = block[j];
00406         if (val == 0) {
00407             run++;
00408         } else {
00409             while (run >= 16) {
00410                 put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
00411                 run -= 16;
00412             }
00413             mant = val;
00414             if (val < 0) {
00415                 val = -val;
00416                 mant--;
00417             }
00418 
00419             nbits= av_log2(val) + 1;
00420             code = (run << 4) | nbits;
00421 
00422             put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
00423 
00424             put_sbits(&s->pb, nbits, mant);
00425             run = 0;
00426         }
00427     }
00428 
00429     /* output EOB only if not already 64 values */
00430     if (last_index < 63 || run != 0)
00431         put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
00432 }
00433 
00434 void ff_mjpeg_encode_mb(MpegEncContext *s, DCTELEM block[6][64])
00435 {
00436     int i;
00437     for(i=0;i<5;i++) {
00438         encode_block(s, block[i], i);
00439     }
00440     if (s->chroma_format == CHROMA_420) {
00441         encode_block(s, block[5], 5);
00442     } else {
00443         encode_block(s, block[6], 6);
00444         encode_block(s, block[5], 5);
00445         encode_block(s, block[7], 7);
00446     }
00447 
00448     s->i_tex_bits += get_bits_diff(s);
00449 }
00450 
00451 // maximum over s->mjpeg_vsample[i]
00452 #define V_MAX 2
00453 static int amv_encode_picture(AVCodecContext *avctx,
00454                        unsigned char *buf, int buf_size, void *data)
00455 {
00456 
00457     AVFrame* pic=data;
00458     MpegEncContext *s = avctx->priv_data;
00459     int i;
00460 
00461     //CODEC_FLAG_EMU_EDGE have to be cleared
00462     if(s->avctx->flags & CODEC_FLAG_EMU_EDGE)
00463         return -1;
00464 
00465     //picture should be flipped upside-down
00466     for(i=0; i < 3; i++) {
00467         pic->data[i] += (pic->linesize[i] * (s->mjpeg_vsample[i] * (8 * s->mb_height -((s->height/V_MAX)&7)) - 1 ));
00468         pic->linesize[i] *= -1;
00469     }
00470     return MPV_encode_picture(avctx,buf, buf_size, pic);
00471 }
00472 
00473 AVCodec ff_mjpeg_encoder = {
00474     .name           = "mjpeg",
00475     .type           = AVMEDIA_TYPE_VIDEO,
00476     .id             = CODEC_ID_MJPEG,
00477     .priv_data_size = sizeof(MpegEncContext),
00478     .init           = MPV_encode_init,
00479     .encode         = MPV_encode_picture,
00480     .close          = MPV_encode_end,
00481     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_NONE},
00482     .long_name= NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),
00483 };
00484 
00485 AVCodec ff_amv_encoder = {
00486     .name           = "amv",
00487     .type           = AVMEDIA_TYPE_VIDEO,
00488     .id             = CODEC_ID_AMV,
00489     .priv_data_size = sizeof(MpegEncContext),
00490     .init           = MPV_encode_init,
00491     .encode         = amv_encode_picture,
00492     .close          = MPV_encode_end,
00493     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_NONE},
00494     .long_name      = NULL_IF_CONFIG_SMALL("AMV Video"),
00495 };
Generated on Fri Feb 1 2013 14:34:38 for FFmpeg by doxygen 1.7.1