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author | Vladimir Voroshilov <voroshil@gmail.com> | 2009-06-20 13:36:21 +0000 |
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committer | Vladimir Voroshilov <voroshil@gmail.com> | 2009-06-20 13:36:21 +0000 |
commit | 630c97ff4b81e5c631c33f1d803d69531f781fb3 (patch) | |
tree | e25de5fd71536821975386053eaaefcea1b0405a /libavcodec/g729dec.c | |
parent | 6ee0eb38c015d7bf139b0058e4d28244830d9d01 (diff) | |
download | ffmpeg-streaming-630c97ff4b81e5c631c33f1d803d69531f781fb3.zip ffmpeg-streaming-630c97ff4b81e5c631c33f1d803d69531f781fb3.tar.gz |
Convertion of LSF values to coefficients of linear prediction filter
Originally committed as revision 19240 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/g729dec.c')
-rw-r--r-- | libavcodec/g729dec.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/libavcodec/g729dec.c b/libavcodec/g729dec.c index 08a3a09..c21e897 100644 --- a/libavcodec/g729dec.c +++ b/libavcodec/g729dec.c @@ -80,6 +80,11 @@ typedef struct { uint8_t fc_indexes_bits; ///< size (in bits) of fixed-codebook index entry } G729FormatDescription; +typedef struct { + int16_t lsp_buf[2][10]; ///< (0.15) LSP coefficients (previous and current frames) (3.2.5) + int16_t *lsp[2]; ///< pointers to lsp_buf +} G729Context; + static const G729FormatDescription format_g729_8k = { .ac_index_bits = {8,5}, .parity_bit = 1, @@ -124,6 +129,10 @@ static av_cold int decoder_init(AVCodecContext * avctx) /* Both 8kbit/s and 6.4kbit/s modes uses two subframes per frame. */ avctx->frame_size = SUBFRAME_SIZE << 1; + ctx->lsp[0] = ctx->lsp_buf[0]; + ctx->lsp[1] = ctx->lsp_buf[1]; + memcpy(ctx->lsp[0], lsp_init, 10 * sizeof(int16_t)); + return 0; } @@ -138,6 +147,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, int frame_erasure = 0; ///< frame erasure detected during decoding int bad_pitch = 0; ///< parity check failed int i; + G729Context *ctx = avctx->priv_data; + int16_t lp[2][11]; // (3.12) uint8_t ma_predictor; ///< switched MA predictor of LSP quantizer uint8_t quantizer_1st; ///< first stage vector of quantizer uint8_t quantizer_2nd_lo; ///< second stage lower vector of quantizer (size in bits) @@ -170,6 +181,12 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, quantizer_2nd_lo = get_bits(&gb, VQ_2ND_BITS); quantizer_2nd_hi = get_bits(&gb, VQ_2ND_BITS); + ff_acelp_lsf2lsp(ctx->lsp[1], ctx->lsfq, 10); + + ff_acelp_lp_decode(&lp[0][0], &lp[1][0], ctx->lsp[1], ctx->lsp[0], 10); + + FFSWAP(int16_t*, ctx->lsp[1], ctx->lsp[0]); + for (i = 0; i < 2; i++) { uint8_t ac_index; ///< adaptive codebook index uint8_t pulses_signs; ///< fixed-codebook vector pulse signs |