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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * MxPEG clip file demuxer |
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| 3 | * Copyright (c) 2010 Anatoly Nenashev |
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| 4 | * |
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| 5 | * This file is part of FFmpeg. |
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| 6 | * |
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| 7 | * FFmpeg is free software; you can redistribute it and/or |
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| 8 | * modify it under the terms of the GNU Lesser General Public |
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| 9 | * License as published by the Free Software Foundation; either |
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| 10 | * version 2.1 of the License, or (at your option) any later version. |
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| 11 | * |
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| 12 | * FFmpeg is distributed in the hope that it will be useful, |
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| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | * Lesser General Public License for more details. |
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| 16 | * |
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| 17 | * You should have received a copy of the GNU Lesser General Public |
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| 18 | * License along with FFmpeg; if not, write to the Free Software |
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| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 20 | */ |
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| 21 | |||
| 22 | #include "libavutil/channel_layout.h" |
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| 23 | #include "libavutil/internal.h" |
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| 24 | #include "libavutil/intreadwrite.h" |
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| 25 | #include "libavcodec/mjpeg.h" |
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| 26 | #include "avformat.h" |
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| 27 | #include "internal.h" |
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| 28 | #include "avio.h" |
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| 29 | |||
| 30 | #define DEFAULT_PACKET_SIZE 1024 |
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| 31 | #define OVERREAD_SIZE 3 |
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| 32 | |||
| 33 | typedef struct MXGContext { |
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| 34 | uint8_t *buffer; |
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| 35 | uint8_t *buffer_ptr; |
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| 36 | uint8_t *soi_ptr; |
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| 37 | unsigned int buffer_size; |
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| 38 | int64_t dts; |
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| 39 | unsigned int cache_size; |
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| 40 | } MXGContext; |
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| 41 | |||
| 42 | static int mxg_read_header(AVFormatContext *s) |
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| 43 | { |
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| 44 | AVStream *video_st, *audio_st; |
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| 45 | MXGContext *mxg = s->priv_data; |
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| 46 | |||
| 47 | /* video parameters will be extracted from the compressed bitstream */ |
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| 48 | video_st = avformat_new_stream(s, NULL); |
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| 49 | if (!video_st) |
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| 50 | return AVERROR(ENOMEM); |
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| 51 | video_st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
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| 52 | video_st->codec->codec_id = AV_CODEC_ID_MXPEG; |
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| 53 | avpriv_set_pts_info(video_st, 64, 1, 1000000); |
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| 54 | |||
| 55 | audio_st = avformat_new_stream(s, NULL); |
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| 56 | if (!audio_st) |
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| 57 | return AVERROR(ENOMEM); |
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| 58 | audio_st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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| 59 | audio_st->codec->codec_id = AV_CODEC_ID_PCM_ALAW; |
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| 60 | audio_st->codec->channels = 1; |
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| 61 | audio_st->codec->channel_layout = AV_CH_LAYOUT_MONO; |
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| 62 | audio_st->codec->sample_rate = 8000; |
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| 63 | audio_st->codec->bits_per_coded_sample = 8; |
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| 64 | audio_st->codec->block_align = 1; |
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| 65 | avpriv_set_pts_info(audio_st, 64, 1, 1000000); |
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| 66 | |||
| 67 | mxg->soi_ptr = mxg->buffer_ptr = mxg->buffer = 0; |
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| 68 | mxg->buffer_size = 0; |
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| 69 | mxg->dts = AV_NOPTS_VALUE; |
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| 70 | mxg->cache_size = 0; |
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| 71 | |||
| 72 | return 0; |
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| 73 | } |
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| 74 | |||
| 75 | static uint8_t* mxg_find_startmarker(uint8_t *p, uint8_t *end) |
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| 76 | { |
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| 77 | for (; p < end - 3; p += 4) { |
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| 78 | uint32_t x = AV_RN32(p); |
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| 79 | |||
| 80 | if (x & (~(x+0x01010101)) & 0x80808080) { |
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| 81 | if (p[0] == 0xff) { |
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| 82 | return p; |
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| 83 | } else if (p[1] == 0xff) { |
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| 84 | return p+1; |
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| 85 | } else if (p[2] == 0xff) { |
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| 86 | return p+2; |
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| 87 | } else if (p[3] == 0xff) { |
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| 88 | return p+3; |
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| 89 | } |
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| 90 | } |
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| 91 | } |
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| 92 | |||
| 93 | for (; p < end; ++p) { |
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| 94 | if (*p == 0xff) return p; |
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| 95 | } |
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| 96 | |||
| 97 | return end; |
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| 98 | } |
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| 99 | |||
| 100 | static int mxg_update_cache(AVFormatContext *s, unsigned int cache_size) |
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| 101 | { |
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| 102 | MXGContext *mxg = s->priv_data; |
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| 103 | unsigned int current_pos = mxg->buffer_ptr - mxg->buffer; |
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| 104 | unsigned int soi_pos; |
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| 105 | uint8_t *buffer; |
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| 106 | int ret; |
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| 107 | |||
| 108 | /* reallocate internal buffer */ |
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| 109 | if (current_pos > current_pos + cache_size) |
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| 110 | return AVERROR(ENOMEM); |
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| 111 | soi_pos = mxg->soi_ptr - mxg->buffer; |
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| 112 | buffer = av_fast_realloc(mxg->buffer, &mxg->buffer_size, |
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| 113 | current_pos + cache_size + |
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| 114 | FF_INPUT_BUFFER_PADDING_SIZE); |
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| 115 | if (!buffer) |
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| 116 | return AVERROR(ENOMEM); |
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| 117 | mxg->buffer = buffer; |
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| 118 | mxg->buffer_ptr = mxg->buffer + current_pos; |
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| 119 | if (mxg->soi_ptr) mxg->soi_ptr = mxg->buffer + soi_pos; |
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| 120 | |||
| 121 | /* get data */ |
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| 122 | ret = avio_read(s->pb, mxg->buffer_ptr + mxg->cache_size, |
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| 123 | cache_size - mxg->cache_size); |
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| 124 | if (ret < 0) |
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| 125 | return ret; |
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| 126 | |||
| 127 | mxg->cache_size += ret; |
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| 128 | |||
| 129 | return ret; |
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| 130 | } |
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| 131 | |||
| 132 | static int mxg_read_packet(AVFormatContext *s, AVPacket *pkt) |
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| 133 | { |
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| 134 | int ret; |
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| 135 | unsigned int size; |
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| 136 | uint8_t *startmarker_ptr, *end, *search_end, marker; |
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| 137 | MXGContext *mxg = s->priv_data; |
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| 138 | |||
| 139 | while (!url_feof(s->pb) && !s->pb->error){ |
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| 140 | if (mxg->cache_size <= OVERREAD_SIZE) { |
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| 141 | /* update internal buffer */ |
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| 142 | ret = mxg_update_cache(s, DEFAULT_PACKET_SIZE + OVERREAD_SIZE); |
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| 143 | if (ret < 0) |
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| 144 | return ret; |
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| 145 | } |
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| 146 | end = mxg->buffer_ptr + mxg->cache_size; |
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| 147 | |||
| 148 | /* find start marker - 0xff */ |
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| 149 | if (mxg->cache_size > OVERREAD_SIZE) { |
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| 150 | search_end = end - OVERREAD_SIZE; |
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| 151 | startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end); |
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| 152 | } else { |
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| 153 | search_end = end; |
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| 154 | startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end); |
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| 155 | if (startmarker_ptr >= search_end - 1 || |
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| 156 | *(startmarker_ptr + 1) != EOI) break; |
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| 157 | } |
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| 158 | |||
| 159 | if (startmarker_ptr != search_end) { /* start marker found */ |
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| 160 | marker = *(startmarker_ptr + 1); |
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| 161 | mxg->buffer_ptr = startmarker_ptr + 2; |
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| 162 | mxg->cache_size = end - mxg->buffer_ptr; |
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| 163 | |||
| 164 | if (marker == SOI) { |
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| 165 | mxg->soi_ptr = startmarker_ptr; |
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| 166 | } else if (marker == EOI) { |
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| 167 | if (!mxg->soi_ptr) { |
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| 168 | av_log(s, AV_LOG_WARNING, "Found EOI before SOI, skipping\n"); |
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| 169 | continue; |
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| 170 | } |
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| 171 | |||
| 172 | pkt->pts = pkt->dts = mxg->dts; |
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| 173 | pkt->stream_index = 0; |
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| 174 | #if FF_API_DESTRUCT_PACKET |
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| 175 | FF_DISABLE_DEPRECATION_WARNINGS |
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| 176 | pkt->destruct = NULL; |
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| 177 | FF_ENABLE_DEPRECATION_WARNINGS |
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| 178 | #endif |
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| 179 | pkt->buf = NULL; |
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| 180 | pkt->size = mxg->buffer_ptr - mxg->soi_ptr; |
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| 181 | pkt->data = mxg->soi_ptr; |
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| 182 | |||
| 183 | if (mxg->soi_ptr - mxg->buffer > mxg->cache_size) { |
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| 184 | if (mxg->cache_size > 0) { |
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| 185 | memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size); |
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| 186 | } |
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| 187 | |||
| 188 | mxg->buffer_ptr = mxg->buffer; |
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| 189 | } |
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| 190 | mxg->soi_ptr = 0; |
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| 191 | |||
| 192 | return pkt->size; |
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| 193 | } else if ( (SOF0 <= marker && marker <= SOF15) || |
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| 194 | (SOS <= marker && marker <= COM) ) { |
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| 195 | /* all other markers that start marker segment also contain |
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| 196 | length value (see specification for JPEG Annex B.1) */ |
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| 197 | size = AV_RB16(mxg->buffer_ptr); |
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| 198 | if (size < 2) |
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| 199 | return AVERROR(EINVAL); |
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| 200 | |||
| 201 | if (mxg->cache_size < size) { |
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| 202 | ret = mxg_update_cache(s, size); |
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| 203 | if (ret < 0) |
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| 204 | return ret; |
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| 205 | startmarker_ptr = mxg->buffer_ptr - 2; |
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| 206 | mxg->cache_size = 0; |
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| 207 | } else { |
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| 208 | mxg->cache_size -= size; |
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| 209 | } |
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| 210 | |||
| 211 | mxg->buffer_ptr += size; |
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| 212 | |||
| 213 | if (marker == APP13 && size >= 16) { /* audio data */ |
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| 214 | /* time (GMT) of first sample in usec since 1970, little-endian */ |
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| 215 | pkt->pts = pkt->dts = AV_RL64(startmarker_ptr + 8); |
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| 216 | pkt->stream_index = 1; |
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| 217 | #if FF_API_DESTRUCT_PACKET |
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| 218 | FF_DISABLE_DEPRECATION_WARNINGS |
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| 219 | pkt->destruct = NULL; |
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| 220 | FF_ENABLE_DEPRECATION_WARNINGS |
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| 221 | #endif |
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| 222 | pkt->buf = NULL; |
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| 223 | pkt->size = size - 14; |
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| 224 | pkt->data = startmarker_ptr + 16; |
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| 225 | |||
| 226 | if (startmarker_ptr - mxg->buffer > mxg->cache_size) { |
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| 227 | if (mxg->cache_size > 0) { |
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| 228 | memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size); |
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| 229 | } |
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| 230 | mxg->buffer_ptr = mxg->buffer; |
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| 231 | } |
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| 232 | |||
| 233 | return pkt->size; |
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| 234 | } else if (marker == COM && size >= 18 && |
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| 235 | !strncmp(startmarker_ptr + 4, "MXF", 3)) { |
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| 236 | /* time (GMT) of video frame in usec since 1970, little-endian */ |
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| 237 | mxg->dts = AV_RL64(startmarker_ptr + 12); |
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| 238 | } |
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| 239 | } |
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| 240 | } else { |
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| 241 | /* start marker not found */ |
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| 242 | mxg->buffer_ptr = search_end; |
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| 243 | mxg->cache_size = OVERREAD_SIZE; |
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| 244 | } |
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| 245 | } |
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| 246 | |||
| 247 | return AVERROR_EOF; |
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| 248 | } |
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| 249 | |||
| 250 | static int mxg_close(struct AVFormatContext *s) |
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| 251 | { |
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| 252 | MXGContext *mxg = s->priv_data; |
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| 253 | av_freep(&mxg->buffer); |
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| 254 | return 0; |
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| 255 | } |
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| 256 | |||
| 257 | AVInputFormat ff_mxg_demuxer = { |
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| 258 | .name = "mxg", |
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| 259 | .long_name = NULL_IF_CONFIG_SMALL("MxPEG clip"), |
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| 260 | .priv_data_size = sizeof(MXGContext), |
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| 261 | .read_header = mxg_read_header, |
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| 262 | .read_packet = mxg_read_packet, |
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| 263 | .read_close = mxg_close, |
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| 264 | .extensions = "mxg", |
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| 265 | }; |