aac5773f
 hucm
功能基本完成，接口待打磨
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/*
* MJPEG A dump header bitstream filter
* Copyright (c) 2006 Baptiste Coudurier
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* MJPEG A dump header bitstream filter
* modifies bitstream to be decoded by quicktime
*/
#include "avcodec.h"
#include "bsf.h"
#include "bytestream.h"
#include "mjpeg.h"
static int mjpega_dump_header(AVBSFContext *ctx, AVPacket *out)
{
AVPacket *in;
uint8_t *out_buf;
unsigned dqt = 0, dht = 0, sof0 = 0;
int ret = 0, i;
ret = ff_bsf_get_packet(ctx, &in);
if (ret < 0)
return ret;
ret = av_new_packet(out, in->size + 44);
if (ret < 0)
goto fail;
ret = av_packet_copy_props(out, in);
if (ret < 0)
goto fail;
out_buf = out->data;
bytestream_put_byte(&out_buf, 0xff);
bytestream_put_byte(&out_buf, SOI);
bytestream_put_byte(&out_buf, 0xff);
bytestream_put_byte(&out_buf, APP1);
bytestream_put_be16(&out_buf, 42); /* size */
bytestream_put_be32(&out_buf, 0);
bytestream_put_buffer(&out_buf, "mjpg", 4);
bytestream_put_be32(&out_buf, in->size + 44); /* field size */
bytestream_put_be32(&out_buf, in->size + 44); /* pad field size */
bytestream_put_be32(&out_buf, 0); /* next ptr */
for (i = 0; i < in->size - 1; i++) {
if (in->data[i] == 0xff) {
switch (in->data[i + 1]) {
case DQT: dqt = i + 46; break;
case DHT: dht = i + 46; break;
case SOF0: sof0 = i + 46; break;
case SOS:
bytestream_put_be32(&out_buf, dqt); /* quant off */
bytestream_put_be32(&out_buf, dht); /* huff off */
bytestream_put_be32(&out_buf, sof0); /* image off */
bytestream_put_be32(&out_buf, i + 46); /* scan off */
bytestream_put_be32(&out_buf, i + 46 + AV_RB16(in->data + i + 2)); /* data off */
bytestream_put_buffer(&out_buf, in->data + 2, in->size - 2); /* skip already written SOI */
out->size = out_buf - out->data;
av_packet_free(&in);
return 0;
case APP1:
if (i + 8 < in->size && AV_RL32(in->data + i + 8) == AV_RL32("mjpg")) {
av_log(ctx, AV_LOG_ERROR, "bitstream already formatted\n");
av_packet_unref(out);
av_packet_move_ref(out, in);
av_packet_free(&in);
return 0;
}
}
}
}
av_log(ctx, AV_LOG_ERROR, "could not find SOS marker in bitstream\n");
fail:
av_packet_unref(out);
av_packet_free(&in);
return AVERROR_INVALIDDATA;
}
static const enum AVCodecID codec_ids[] = {
AV_CODEC_ID_MJPEG, AV_CODEC_ID_NONE,
};
const AVBitStreamFilter ff_mjpega_dump_header_bsf = {
.name = "mjpegadump",
.filter = mjpega_dump_header,
.codec_ids = codec_ids,
};
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