mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
168 lines
5.2 KiB
168 lines
5.2 KiB
/* |
|
* 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 |
|
}, |
|
};
|
|
|