ffmpeg / libavcodec / ljpegenc.c @ 755bfeab
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/*


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* lossless JPEG encoder

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* Copyright (c) 2000, 2001 Fabrice Bellard.

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* Copyright (c) 2003 Alex Beregszaszi

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* Copyright (c) 20032004 Michael Niedermayer

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*

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* This file is part of FFmpeg.

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*

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* FFmpeg is free software; you can redistribute it and/or

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* modify it under the terms of the GNU Lesser General Public

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* License as published by the Free Software Foundation; either

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* version 2.1 of the License, or (at your option) any later version.

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*

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* FFmpeg is distributed in the hope that it will be useful,

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* but WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* Lesser General Public License for more details.

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*

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* You should have received a copy of the GNU Lesser General Public

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* License along with FFmpeg; if not, write to the Free Software

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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 021101301 USA

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*

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* Support for external huffman table, various fixes (AVID workaround),

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* aspecting, new decode_frame mechanism and apple mjpegb support

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* by Alex Beregszaszi

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*/

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/**

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* @file ljpegenc.c

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* lossless JPEG encoder.

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*/

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#include "avcodec.h" 
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#include "dsputil.h" 
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#include "mpegvideo.h" 
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#include "mjpeg.h" 
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#include "mjpegenc.h" 
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static int encode_picture_lossless(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){ 
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MpegEncContext * const s = avctx>priv_data;

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MJpegContext * const m = s>mjpeg_ctx;

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AVFrame *pict = data; 
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const int width= s>width; 
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const int height= s>height; 
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AVFrame * const p= (AVFrame*)&s>current_picture;

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const int predictor= avctx>prediction_method+1; 
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init_put_bits(&s>pb, buf, buf_size); 
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*p = *pict; 
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p>pict_type= FF_I_TYPE; 
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p>key_frame= 1;

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ff_mjpeg_encode_picture_header(s); 
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s>header_bits= put_bits_count(&s>pb); 
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if(avctx>pix_fmt == PIX_FMT_RGB32){

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int x, y, i;

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const int linesize= p>linesize[0]; 
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uint16_t (*buffer)[4]= (void *) s>rd_scratchpad; 
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int left[3], top[3], topleft[3]; 
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for(i=0; i<3; i++){ 
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buffer[0][i]= 1 << (9  1); 
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} 
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for(y = 0; y < height; y++) { 
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const int modified_predictor= y ? predictor : 1; 
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uint8_t *ptr = p>data[0] + (linesize * y);

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if(s>pb.buf_end  s>pb.buf  (put_bits_count(&s>pb)>>3) < width*3*4){ 
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av_log(s>avctx, AV_LOG_ERROR, "encoded frame too large\n");

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return 1; 
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} 
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for(i=0; i<3; i++){ 
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top[i]= left[i]= topleft[i]= buffer[0][i];

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} 
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for(x = 0; x < width; x++) { 
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buffer[x][1] = ptr[4*x+0]  ptr[4*x+1] + 0x100; 
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buffer[x][2] = ptr[4*x+2]  ptr[4*x+1] + 0x100; 
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buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2; 
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for(i=0;i<3;i++) { 
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int pred, diff;

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PREDICT(pred, topleft[i], top[i], left[i], modified_predictor); 
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topleft[i]= top[i]; 
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top[i]= buffer[x+1][i];

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left[i]= buffer[x][i]; 
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diff= ((left[i]  pred + 0x100)&0x1FF)  0x100; 
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if(i==0) 
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ff_mjpeg_encode_dc(s, diff, m>huff_size_dc_luminance, m>huff_code_dc_luminance); //FIXME ugly

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else

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ff_mjpeg_encode_dc(s, diff, m>huff_size_dc_chrominance, m>huff_code_dc_chrominance); 
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} 
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} 
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} 
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}else{

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int mb_x, mb_y, i;

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const int mb_width = (width + s>mjpeg_hsample[0]  1) / s>mjpeg_hsample[0]; 
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const int mb_height = (height + s>mjpeg_vsample[0]  1) / s>mjpeg_vsample[0]; 
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for(mb_y = 0; mb_y < mb_height; mb_y++) { 
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if(s>pb.buf_end  s>pb.buf  (put_bits_count(&s>pb)>>3) < mb_width * 4 * 3 * s>mjpeg_hsample[0] * s>mjpeg_vsample[0]){ 
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av_log(s>avctx, AV_LOG_ERROR, "encoded frame too large\n");

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return 1; 
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} 
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for(mb_x = 0; mb_x < mb_width; mb_x++) { 
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if(mb_x==0  mb_y==0){ 
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for(i=0;i<3;i++) { 
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uint8_t *ptr; 
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int x, y, h, v, linesize;

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h = s>mjpeg_hsample[i]; 
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v = s>mjpeg_vsample[i]; 
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linesize= p>linesize[i]; 
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for(y=0; y<v; y++){ 
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for(x=0; x<h; x++){ 
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int pred;

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ptr = p>data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap

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if(y==0 && mb_y==0){ 
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if(x==0 && mb_x==0){ 
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pred= 128;

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}else{

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pred= ptr[1];

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} 
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}else{

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if(x==0 && mb_x==0){ 
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pred= ptr[linesize]; 
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}else{

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PREDICT(pred, ptr[linesize1], ptr[linesize], ptr[1], predictor); 
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} 
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} 
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if(i==0) 
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ff_mjpeg_encode_dc(s, (int8_t)(*ptr  pred), m>huff_size_dc_luminance, m>huff_code_dc_luminance); //FIXME ugly

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else

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ff_mjpeg_encode_dc(s, (int8_t)(*ptr  pred), m>huff_size_dc_chrominance, m>huff_code_dc_chrominance); 
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} 
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} 
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} 
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}else{

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for(i=0;i<3;i++) { 
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uint8_t *ptr; 
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int x, y, h, v, linesize;

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h = s>mjpeg_hsample[i]; 
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v = s>mjpeg_vsample[i]; 
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linesize= p>linesize[i]; 
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for(y=0; y<v; y++){ 
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for(x=0; x<h; x++){ 
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int pred;

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ptr = p>data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap

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//printf("%d %d %d %d %8X\n", mb_x, mb_y, x, y, ptr);

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PREDICT(pred, ptr[linesize1], ptr[linesize], ptr[1], predictor); 
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if(i==0) 
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ff_mjpeg_encode_dc(s, (int8_t)(*ptr  pred), m>huff_size_dc_luminance, m>huff_code_dc_luminance); //FIXME ugly

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else

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ff_mjpeg_encode_dc(s, (int8_t)(*ptr  pred), m>huff_size_dc_chrominance, m>huff_code_dc_chrominance); 
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} 
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} 
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} 
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} 
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} 
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} 
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} 
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emms_c(); 
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ff_mjpeg_encode_picture_trailer(s); 
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s>picture_number++; 
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flush_put_bits(&s>pb); 
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return pbBufPtr(&s>pb)  s>pb.buf;

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// return (put_bits_count(&f>pb)+7)/8;

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} 
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AVCodec ljpeg_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them

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"ljpeg",

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CODEC_TYPE_VIDEO, 
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CODEC_ID_LJPEG, 
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sizeof(MpegEncContext),

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MPV_encode_init, 
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encode_picture_lossless, 
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MPV_encode_end, 
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}; 