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| author | Justin Ruggles <justin.ruggles@gmail.com> | 2011-11-20 14:21:32 -0500 |
|---|---|---|
| committer | Justin Ruggles <justin.ruggles@gmail.com> | 2011-11-26 16:25:06 -0500 |
| commit | b237248e297760648307356efa5fcbfe16844829 (patch) | |
| tree | 76ac03216c87ddc68904f9abe3e1e5a89c25604b /libavcodec/adxdec.c | |
| parent | 954d94dd5e13ba7a5e9e049d0f980bddced9644c (diff) | |
| download | ffmpeg-b237248e297760648307356efa5fcbfe16844829.tar.gz | |
adx: calculate correct LPC coeffs
Instead of using fixed coefficients, the correct way is to calculate the
coefficients using the highpass cutoff frequency from the ADX stream header
and the sample rate.
Diffstat (limited to 'libavcodec/adxdec.c')
| -rw-r--r-- | libavcodec/adxdec.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/libavcodec/adxdec.c b/libavcodec/adxdec.c index 93bbc6b51b..f9f17cde95 100644 --- a/libavcodec/adxdec.c +++ b/libavcodec/adxdec.c @@ -59,7 +59,7 @@ static void adx_decode(ADXContext *c, int16_t *out, const uint8_t *in, int ch) s2 = prev->s2; for (i = 0; i < 32; i++) { d = get_sbits(&gb, 4); - s0 = ((d << COEFF_BITS) * scale + COEFF1 * s1 - COEFF2 * s2) >> COEFF_BITS; + s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS; s2 = s1; s1 = av_clip_int16(s0); *out = s1; @@ -81,7 +81,7 @@ static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, int bufsize) { ADXContext *c = avctx->priv_data; - int offset; + int offset, cutoff; if (AV_RB16(buf) != 0x8000) return AVERROR_INVALIDDATA; @@ -98,6 +98,9 @@ static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf, return AVERROR_INVALIDDATA; avctx->bit_rate = avctx->sample_rate * avctx->channels * 18 * 8 / 32; + cutoff = AV_RB16(buf + 16); + ff_adx_calculate_coeffs(cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); + return offset; } |