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#include "libavutil/intreadwrite.h" |
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#include "libavutil/internal.h" |
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#include "avformat.h" |
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#include "internal.h" |
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#include "rawdec.h" |
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#define LOAS_SYNC_WORD 0x2b7 |
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static int loas_probe(const AVProbeData *p) |
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{ |
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int max_frames = 0, first_frames = 0; |
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int fsize, frames; |
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const uint8_t *buf0 = p->buf; |
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const uint8_t *buf2; |
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const uint8_t *buf; |
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const uint8_t *end = buf0 + p->buf_size - 3; |
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buf = buf0; |
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for (; buf < end; buf = buf2 + 1) { |
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buf2 = buf; |
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for (frames = 0; buf2 < end; frames++) { |
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uint32_t header = AV_RB24(buf2); |
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if ((header >> 13) != LOAS_SYNC_WORD) |
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break; |
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fsize = (header & 0x1FFF) + 3; |
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if (fsize < 7) |
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break; |
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fsize = FFMIN(fsize, end - buf2); |
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buf2 += fsize; |
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} |
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max_frames = FFMAX(max_frames, frames); |
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if (buf == buf0) |
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first_frames = frames; |
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} |
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if (first_frames >= 3) |
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return AVPROBE_SCORE_EXTENSION + 1; |
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else if (max_frames > 100) |
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return AVPROBE_SCORE_EXTENSION; |
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else if (max_frames >= 3) |
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return AVPROBE_SCORE_EXTENSION / 2; |
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else |
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return 0; |
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} |
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static int loas_read_header(AVFormatContext *s) |
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{ |
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AVStream *st; |
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st = avformat_new_stream(s, NULL); |
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if (!st) |
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return AVERROR(ENOMEM); |
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st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
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st->codecpar->codec_id = s->iformat->raw_codec_id; |
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ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL_RAW; |
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avpriv_set_pts_info(st, 64, 1, 28224000); |
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return 0; |
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} |
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const AVInputFormat ff_loas_demuxer = { |
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.name = "loas", |
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.long_name = NULL_IF_CONFIG_SMALL("LOAS AudioSyncStream"), |
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.read_probe = loas_probe, |
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.read_header = loas_read_header, |
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.read_packet = ff_raw_read_partial_packet, |
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.flags= AVFMT_GENERIC_INDEX, |
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.raw_codec_id = AV_CODEC_ID_AAC_LATM, |
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.priv_data_size = sizeof(FFRawDemuxerContext), |
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.priv_class = &ff_raw_demuxer_class, |
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}; |
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