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/*
* MJPEG/AVI1 to JPEG/JFIF bitstream format filter
* Copyright (c) 2010 Adrian Daerr and Nicolas George
*
* 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
*/
/*
* Adapted from mjpeg2jpeg.c, with original copyright:
* Paris 2010 Adrian Daerr, public domain
*/
#include <string.h>
#include "libavutil/error.h"
#include "libavutil/mem.h"
#include "avcodec.h"
#include "mjpeg.h"
static const uint8_t jpeg_header[] = {
0xff, 0xd8, // SOI
0xff, 0xe0, // APP0
0x00, 0x10, // APP0 header size (including
// this field, but excluding preceding)
0x4a, 0x46, 0x49, 0x46, 0x00, // ID string 'JFIF\0'
0x01, 0x01, // version
0x00, // bits per type
0x00, 0x00, // X density
0x00, 0x00, // Y density
0x00, // X thumbnail size
0x00, // Y thumbnail size
};
static const int dht_segment_size = 420;
static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
static const uint8_t dht_segment_frag[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
};
static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
{
memcpy(buf, src, size);
return buf + size;
}
static uint8_t *append_dht_segment(uint8_t *buf)
{
buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
buf = append(buf, avpriv_mjpeg_bits_dc_luminance + 1, 16);
buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
buf = append(buf, avpriv_mjpeg_val_dc, 12);
*(buf++) = 0x10;
buf = append(buf, avpriv_mjpeg_bits_ac_luminance + 1, 16);
buf = append(buf, avpriv_mjpeg_val_ac_luminance, 162);
*(buf++) = 0x11;
buf = append(buf, avpriv_mjpeg_bits_ac_chrominance + 1, 16);
buf = append(buf, avpriv_mjpeg_val_ac_chrominance, 162);
return buf;
}
static int mjpeg2jpeg_filter(AVBitStreamFilterContext *bsfc,
AVCodecContext *avctx, const char *args,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size,
int keyframe)
{
int input_skip, output_size;
uint8_t *output, *out;
if (buf_size < 12) {
av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
return AVERROR_INVALIDDATA;
}
if (memcmp("AVI1", buf + 6, 4)) {
av_log(avctx, AV_LOG_ERROR, "input is not MJPEG/AVI1\n");
return AVERROR_INVALIDDATA;
}
input_skip = (buf[4] << 8) + buf[5] + 4;
if (buf_size < input_skip) {
av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
return AVERROR_INVALIDDATA;
}
output_size = buf_size - input_skip +
sizeof(jpeg_header) + dht_segment_size;
output = out = av_malloc(output_size);
if (!output)
return AVERROR(ENOMEM);
out = append(out, jpeg_header, sizeof(jpeg_header));
out = append_dht_segment(out);
out = append(out, buf + input_skip, buf_size - input_skip);
*poutbuf = output;
*poutbuf_size = output_size;
return 1;
}
AVBitStreamFilter ff_mjpeg2jpeg_bsf = {
.name = "mjpeg2jpeg",
.filter = mjpeg2jpeg_filter,
};
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