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/*
* MJPEG encoder
* Copyright (c) 2000, 2001 Fabrice Bellard
* Copyright (c) 2003 Alex Beregszaszi
* Copyright (c) 2003-2004 Michael Niedermayer
*
* Support for external huffman table, various fixes (AVID workaround),
* aspecting, new decode_frame mechanism and apple mjpeg-b support
* by Alex Beregszaszi
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* MJPEG encoder.
*/
#include <assert.h>
#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "mjpegenc_common.h"
#include "mpegvideo.h"
#include "mjpeg.h"
#include "mjpegenc.h"
av_cold int ff_mjpeg_encode_init(MpegEncContext *s)
{
MJpegContext *m;
m = av_malloc(sizeof(MJpegContext));
if (!m)
return AVERROR(ENOMEM);
s->min_qcoeff=-1023;
s->max_qcoeff= 1023;
/* build all the huffman tables */
ff_mjpeg_build_huffman_codes(m->huff_size_dc_luminance,
m->huff_code_dc_luminance,
avpriv_mjpeg_bits_dc_luminance,
avpriv_mjpeg_val_dc);
ff_mjpeg_build_huffman_codes(m->huff_size_dc_chrominance,
m->huff_code_dc_chrominance,
avpriv_mjpeg_bits_dc_chrominance,
avpriv_mjpeg_val_dc);
ff_mjpeg_build_huffman_codes(m->huff_size_ac_luminance,
m->huff_code_ac_luminance,
avpriv_mjpeg_bits_ac_luminance,
avpriv_mjpeg_val_ac_luminance);
ff_mjpeg_build_huffman_codes(m->huff_size_ac_chrominance,
m->huff_code_ac_chrominance,
avpriv_mjpeg_bits_ac_chrominance,
avpriv_mjpeg_val_ac_chrominance);
s->mjpeg_ctx = m;
return 0;
}
void ff_mjpeg_encode_close(MpegEncContext *s)
{
av_free(s->mjpeg_ctx);
}
static void encode_block(MpegEncContext *s, int16_t *block, int n)
{
int mant, nbits, code, i, j;
int component, dc, run, last_index, val;
MJpegContext *m = s->mjpeg_ctx;
uint8_t *huff_size_ac;
uint16_t *huff_code_ac;
/* DC coef */
component = (n <= 3 ? 0 : (n&1) + 1);
dc = block[0]; /* overflow is impossible */
val = dc - s->last_dc[component];
if (n < 4) {
ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance);
huff_size_ac = m->huff_size_ac_luminance;
huff_code_ac = m->huff_code_ac_luminance;
} else {
ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
huff_size_ac = m->huff_size_ac_chrominance;
huff_code_ac = m->huff_code_ac_chrominance;
}
s->last_dc[component] = dc;
/* AC coefs */
run = 0;
last_index = s->block_last_index[n];
for(i=1;i<=last_index;i++) {
j = s->intra_scantable.permutated[i];
val = block[j];
if (val == 0) {
run++;
} else {
while (run >= 16) {
put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
run -= 16;
}
mant = val;
if (val < 0) {
val = -val;
mant--;
}
nbits= av_log2(val) + 1;
code = (run << 4) | nbits;
put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
put_sbits(&s->pb, nbits, mant);
run = 0;
}
}
/* output EOB only if not already 64 values */
if (last_index < 63 || run != 0)
put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
}
void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[6][64])
{
int i;
for(i=0;i<5;i++) {
encode_block(s, block[i], i);
}
if (s->chroma_format == CHROMA_420) {
encode_block(s, block[5], 5);
} else {
encode_block(s, block[6], 6);
encode_block(s, block[5], 5);
encode_block(s, block[7], 7);
}
s->i_tex_bits += get_bits_diff(s);
}
AVCodec ff_mjpeg_encoder = {
.name = "mjpeg",
.long_name = NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MJPEG,
.priv_data_size = sizeof(MpegEncContext),
.init = ff_mpv_encode_init,
.encode2 = ff_mpv_encode_picture,
.close = ff_mpv_encode_end,
.pix_fmts = (const enum AVPixelFormat[]){
AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_NONE
},
};
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