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ffmpeg / libavcodec / ljpegenc.c @ 2912e87a

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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) 2003-2004 Michael Niedermayer
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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 mjpeg-b support
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 *                                  by Alex Beregszaszi
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 *
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 * This file is part of Libav.
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 *
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 * Libav 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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 * Libav 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 Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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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_BGRA){
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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[-linesize-1], 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, *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, *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[-linesize-1], ptr[-linesize], ptr[-1], predictor);
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                                if(i==0)
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                                    ff_mjpeg_encode_dc(s, *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, *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 put_bits_ptr(&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 ff_ljpeg_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them
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    "ljpeg",
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    AVMEDIA_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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    .long_name = NULL_IF_CONFIG_SMALL("Lossless JPEG"),
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};