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109 lines
3.6 KiB
C
109 lines
3.6 KiB
C
/*
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* MJPEG A dump header bitstream filter
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* Copyright (c) 2006 Baptiste Coudurier
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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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* MJPEG A dump header bitstream filter
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* modifies bitstream to be decoded by quicktime
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*/
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#include "avcodec.h"
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#include "bsf.h"
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#include "bytestream.h"
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#include "mjpeg.h"
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static int mjpega_dump_header(AVBSFContext *ctx, AVPacket *out)
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{
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AVPacket *in;
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uint8_t *out_buf;
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unsigned dqt = 0, dht = 0, sof0 = 0;
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int ret = 0, i;
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ret = ff_bsf_get_packet(ctx, &in);
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if (ret < 0)
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return ret;
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ret = av_new_packet(out, in->size + 44);
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if (ret < 0)
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goto fail;
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ret = av_packet_copy_props(out, in);
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if (ret < 0)
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goto fail;
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out_buf = out->data;
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bytestream_put_byte(&out_buf, 0xff);
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bytestream_put_byte(&out_buf, SOI);
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bytestream_put_byte(&out_buf, 0xff);
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bytestream_put_byte(&out_buf, APP1);
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bytestream_put_be16(&out_buf, 42); /* size */
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bytestream_put_be32(&out_buf, 0);
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bytestream_put_buffer(&out_buf, "mjpg", 4);
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bytestream_put_be32(&out_buf, in->size + 44); /* field size */
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bytestream_put_be32(&out_buf, in->size + 44); /* pad field size */
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bytestream_put_be32(&out_buf, 0); /* next ptr */
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for (i = 0; i < in->size - 1; i++) {
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if (in->data[i] == 0xff) {
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switch (in->data[i + 1]) {
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case DQT: dqt = i + 46; break;
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case DHT: dht = i + 46; break;
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case SOF0: sof0 = i + 46; break;
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case SOS:
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bytestream_put_be32(&out_buf, dqt); /* quant off */
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bytestream_put_be32(&out_buf, dht); /* huff off */
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bytestream_put_be32(&out_buf, sof0); /* image off */
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bytestream_put_be32(&out_buf, i + 46); /* scan off */
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bytestream_put_be32(&out_buf, i + 46 + AV_RB16(in->data + i + 2)); /* data off */
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bytestream_put_buffer(&out_buf, in->data + 2, in->size - 2); /* skip already written SOI */
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out->size = out_buf - out->data;
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av_packet_free(&in);
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return 0;
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case APP1:
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if (i + 8 < in->size && AV_RL32(in->data + i + 8) == AV_RL32("mjpg")) {
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av_log(ctx, AV_LOG_ERROR, "bitstream already formatted\n");
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av_packet_unref(out);
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av_packet_move_ref(out, in);
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av_packet_free(&in);
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return 0;
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}
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}
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}
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}
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av_log(ctx, AV_LOG_ERROR, "could not find SOS marker in bitstream\n");
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fail:
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av_packet_unref(out);
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av_packet_free(&in);
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return AVERROR_INVALIDDATA;
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}
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static const enum AVCodecID codec_ids[] = {
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AV_CODEC_ID_MJPEG, AV_CODEC_ID_NONE,
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};
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const AVBitStreamFilter ff_mjpega_dump_header_bsf = {
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.name = "mjpegadump",
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.filter = mjpega_dump_header,
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.codec_ids = codec_ids,
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};
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