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@ -27,13 +27,50 @@ |
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#ifndef AVCODEC_MPEGAUDIODECHEADER_H |
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#define AVCODEC_MPEGAUDIODECHEADER_H |
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#include "libavutil/common.h" |
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#include "mpegaudio.h" |
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#include "avcodec.h" |
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#define MP3_MASK 0xFFFE0CCF |
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#define MPA_DECODE_HEADER \ |
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int frame_size; \
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int error_protection; \
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int layer; \
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int sample_rate; \
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int sample_rate_index; /* between 0 and 8 */ \
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int bit_rate; \
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int nb_channels; \
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int mode; \
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int mode_ext; \
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int lsf; |
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typedef struct MPADecodeHeader { |
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MPA_DECODE_HEADER |
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} MPADecodeHeader; |
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/* header decoding. MUST check the header before because no
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consistency check is done there. Return 1 if free format found and |
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that the frame size must be computed externally */ |
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int ff_mpegaudio_decode_header(MPADecodeHeader *s, uint32_t header); |
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/* useful helper to get mpeg audio stream infos. Return -1 if error in
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header, otherwise the coded frame size in bytes */ |
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int ff_mpa_decode_header(AVCodecContext *avctx, uint32_t head, int *sample_rate, int *channels, int *frame_size, int *bitrate); |
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/* fast header check for resync */ |
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static inline int ff_mpa_check_header(uint32_t header){ |
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/* header */ |
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if ((header & 0xffe00000) != 0xffe00000) |
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return -1; |
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/* layer check */ |
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if ((header & (3<<17)) == 0) |
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return -1; |
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/* bit rate */ |
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if ((header & (0xf<<12)) == 0xf<<12) |
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return -1; |
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/* frequency */ |
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if ((header & (3<<10)) == 3<<10) |
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return -1; |
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return 0; |
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} |
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#endif /* AVCODEC_MPEGAUDIODECHEADER_H */ |
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