mirror of https://github.com/FFmpeg/FFmpeg.git
Patch by Anatoly Nenashev, anatoly d nenashev a ovsoft d ru Originally committed as revision 25831 to svn://svn.ffmpeg.org/ffmpeg/trunkoldabi
Anatoly Nenashev
14 years ago
committed by
Carl Eugen Hoyos
parent
d6adf44b06
commit
9d09ebf1ed
7 changed files with 258 additions and 2 deletions
@ -0,0 +1,251 @@ |
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/*
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* MxPEG clip file demuxer |
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* Copyright (c) 2010 Anatoly Nenashev |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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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#include "libavutil/intreadwrite.h" |
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#include "libavcodec/mjpeg.h" |
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#include "avformat.h" |
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#include "avio.h" |
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#define VIDEO_STREAM_INDEX 0 |
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#define AUDIO_STREAM_INDEX 1 |
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#define DEFAULT_PACKET_SIZE 1024 |
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#define OVERREAD_SIZE 3 |
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typedef struct MXGContext { |
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uint8_t *buffer; |
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uint8_t *buffer_ptr; |
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uint8_t *soi_ptr; |
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unsigned int buffer_size; |
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int64_t dts; |
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unsigned int cache_size; |
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} MXGContext; |
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static int mxg_read_header(AVFormatContext *s, AVFormatParameters *ap) |
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{ |
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AVStream *video_st, *audio_st; |
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MXGContext *mxg = s->priv_data; |
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/* video parameters will be extracted from the compressed bitstream */ |
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video_st = av_new_stream(s, VIDEO_STREAM_INDEX); |
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if (!video_st) |
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return AVERROR(ENOMEM); |
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video_st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
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video_st->codec->codec_id = CODEC_ID_MXPEG; |
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av_set_pts_info(video_st, 64, 1, 1000000); |
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audio_st = av_new_stream(s, AUDIO_STREAM_INDEX); |
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if (!audio_st) |
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return AVERROR(ENOMEM); |
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audio_st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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audio_st->codec->codec_id = CODEC_ID_PCM_ALAW; |
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audio_st->codec->channels = 1; |
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audio_st->codec->sample_rate = 8000; |
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audio_st->codec->bits_per_coded_sample = 8; |
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audio_st->codec->block_align = 1; |
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av_set_pts_info(audio_st, 64, 1, 1000000); |
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mxg->soi_ptr = mxg->buffer_ptr = mxg->buffer = 0; |
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mxg->buffer_size = 0; |
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mxg->dts = AV_NOPTS_VALUE; |
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mxg->cache_size = 0; |
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return 0; |
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} |
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static uint8_t* mxg_find_startmarker(uint8_t *p, uint8_t *end) |
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{ |
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for (; p < end - 3; p += 4) { |
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uint32_t x = *(uint32_t*)p; |
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if (x & (~(x+0x01010101)) & 0x80808080) { |
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if (p[0] == 0xff) { |
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return p; |
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} else if (p[1] == 0xff) { |
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return p+1; |
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} else if (p[2] == 0xff) { |
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return p+2; |
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} else if (p[3] == 0xff) { |
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return p+3; |
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} |
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} |
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} |
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for (; p < end; ++p) { |
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if (*p == 0xff) return p; |
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} |
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return end; |
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} |
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static int mxg_update_cache(AVFormatContext *s, unsigned int cache_size) |
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{ |
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MXGContext *mxg = s->priv_data; |
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unsigned int current_pos = mxg->buffer_ptr - mxg->buffer; |
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unsigned int soi_pos; |
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int ret; |
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/* reallocate internal buffer */ |
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if (current_pos > current_pos + cache_size) |
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return AVERROR(ENOMEM); |
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if (mxg->soi_ptr) soi_pos = mxg->soi_ptr - mxg->buffer; |
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mxg->buffer = av_fast_realloc(mxg->buffer, &mxg->buffer_size, |
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current_pos + cache_size + |
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FF_INPUT_BUFFER_PADDING_SIZE); |
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if (!mxg->buffer) |
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return AVERROR(ENOMEM); |
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mxg->buffer_ptr = mxg->buffer + current_pos; |
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if (mxg->soi_ptr) mxg->soi_ptr = mxg->buffer + soi_pos; |
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/* get data */ |
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ret = get_buffer(s->pb, mxg->buffer_ptr + mxg->cache_size, |
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cache_size - mxg->cache_size); |
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if (ret < 0) |
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return ret; |
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mxg->cache_size += ret; |
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return ret; |
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} |
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static int mxg_read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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int ret; |
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unsigned int size; |
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uint8_t *startmarker_ptr, *end, *search_end, marker; |
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MXGContext *mxg = s->priv_data; |
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while (!url_feof(s->pb) && !url_ferror(s->pb)){ |
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if (mxg->cache_size <= OVERREAD_SIZE) { |
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/* update internal buffer */ |
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ret = mxg_update_cache(s, DEFAULT_PACKET_SIZE + OVERREAD_SIZE); |
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if (ret < 0) |
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return ret; |
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} |
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end = mxg->buffer_ptr + mxg->cache_size; |
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/* find start marker - 0xff */ |
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if (mxg->cache_size > OVERREAD_SIZE) { |
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search_end = end - OVERREAD_SIZE; |
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startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end); |
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} else { |
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search_end = end; |
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startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end); |
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if (startmarker_ptr >= search_end - 1 || |
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*(startmarker_ptr + 1) != EOI) break; |
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} |
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if (startmarker_ptr != search_end) { /* start marker found */ |
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marker = *(startmarker_ptr + 1); |
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mxg->buffer_ptr = startmarker_ptr + 2; |
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mxg->cache_size = end - mxg->buffer_ptr; |
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if (marker == SOI) { |
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mxg->soi_ptr = startmarker_ptr; |
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} else if (marker == EOI) { |
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if (!mxg->soi_ptr) { |
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av_log(s, AV_LOG_WARNING, "Found EOI before SOI, skipping\n"); |
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continue; |
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} |
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pkt->pts = pkt->dts = mxg->dts; |
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pkt->stream_index = VIDEO_STREAM_INDEX; |
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pkt->destruct = NULL; |
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pkt->size = mxg->buffer_ptr - mxg->soi_ptr; |
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pkt->data = mxg->soi_ptr; |
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if (mxg->soi_ptr - mxg->buffer > mxg->cache_size) { |
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if (mxg->cache_size > 0) { |
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memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size); |
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} |
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mxg->buffer_ptr = mxg->buffer; |
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} |
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mxg->soi_ptr = 0; |
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return pkt->size; |
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} else if ( (SOF0 <= marker && marker <= SOF15) || |
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(SOS <= marker && marker <= COM) ) { |
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/* all other markers that start marker segment also contain
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length value (see specification for JPEG Annex B.1) */ |
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size = AV_RB16(mxg->buffer_ptr); |
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if (size < 2) |
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return AVERROR(EINVAL); |
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if (mxg->cache_size < size) { |
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ret = mxg_update_cache(s, size); |
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if (ret < 0) |
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return ret; |
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startmarker_ptr = mxg->buffer_ptr - 2; |
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mxg->cache_size = 0; |
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} else { |
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mxg->cache_size -= size; |
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} |
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mxg->buffer_ptr += size; |
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if (marker == APP13 && size >= 16) { /* audio data */ |
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/* time (GMT) of first sample in usec since 1970, little-endian */ |
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pkt->pts = pkt->dts = AV_RL64(startmarker_ptr + 8); |
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pkt->stream_index = AUDIO_STREAM_INDEX; |
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pkt->destruct = NULL; |
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pkt->size = size - 14; |
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pkt->data = startmarker_ptr + 16; |
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if (startmarker_ptr - mxg->buffer > mxg->cache_size) { |
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if (mxg->cache_size > 0) { |
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memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size); |
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} |
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mxg->buffer_ptr = mxg->buffer; |
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} |
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return pkt->size; |
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} else if (marker == COM && size >= 18 && |
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!strncmp(startmarker_ptr + 4, "MXF", 3)) { |
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/* time (GMT) of video frame in usec since 1970, little-endian */ |
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mxg->dts = AV_RL64(startmarker_ptr + 12); |
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} |
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} |
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} else { |
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/* start marker not found */ |
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mxg->buffer_ptr = search_end; |
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mxg->cache_size = OVERREAD_SIZE; |
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} |
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} |
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return AVERROR_EOF; |
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} |
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static int mxg_close(struct AVFormatContext *s) |
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{ |
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MXGContext *mxg = s->priv_data; |
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av_freep(&mxg->buffer); |
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return 0; |
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} |
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AVInputFormat mxg_demuxer = { |
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.name = "mxg", |
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.long_name = NULL_IF_CONFIG_SMALL("MxPEG clip file format"), |
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.priv_data_size = sizeof(MXGContext), |
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.read_header = mxg_read_header, |
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.read_packet = mxg_read_packet, |
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.read_close = mxg_close, |
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.extensions = "mxg" |
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}; |
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