diff options
| -rw-r--r-- | libavcodec/Makefile | 2 | ||||
| -rw-r--r-- | libavcodec/adx.c | 34 | ||||
| -rw-r--r-- | libavcodec/adx.h | 14 | ||||
| -rw-r--r-- | libavcodec/adxdec.c | 7 | ||||
| -rw-r--r-- | libavcodec/adxenc.c | 27 |
5 files changed, 70 insertions, 14 deletions
diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 37aa8ee331..2cdcca2cfc 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -489,7 +489,7 @@ OBJS-$(CONFIG_PCM_U32LE_ENCODER) += pcm.o OBJS-$(CONFIG_PCM_ZORK_DECODER) += pcm.o OBJS-$(CONFIG_ADPCM_4XM_DECODER) += adpcm.o adpcm_data.o -OBJS-$(CONFIG_ADPCM_ADX_DECODER) += adxdec.o +OBJS-$(CONFIG_ADPCM_ADX_DECODER) += adxdec.o adx.o OBJS-$(CONFIG_ADPCM_ADX_ENCODER) += adxenc.o OBJS-$(CONFIG_ADPCM_CT_DECODER) += adpcm.o adpcm_data.o OBJS-$(CONFIG_ADPCM_EA_DECODER) += adpcm.o diff --git a/libavcodec/adx.c b/libavcodec/adx.c new file mode 100644 index 0000000000..bc3e8825ca --- /dev/null +++ b/libavcodec/adx.c @@ -0,0 +1,34 @@ +/* + * Copyright (c) 2011 Justin Ruggles + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/mathematics.h" +#include "adx.h" + +void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff) +{ + double a, b, c; + + a = M_SQRT2 - cos(2.0 * M_PI * cutoff / sample_rate); + b = M_SQRT2 - 1.0; + c = (a - sqrt((a + b) * (a - b))) / b; + + coeff[0] = lrintf(c * 2.0 * (1 << bits)); + coeff[1] = lrintf(-(c * c) * (1 << bits)); +} diff --git a/libavcodec/adx.h b/libavcodec/adx.h index ae5eb6a434..cd8c45bf6d 100644 --- a/libavcodec/adx.h +++ b/libavcodec/adx.h @@ -41,10 +41,20 @@ typedef struct { int header_parsed; unsigned char dec_temp[18*2]; int in_temp; + int cutoff; + int coeff[2]; } ADXContext; #define COEFF_BITS 12 -#define COEFF1 0x1CA6 -#define COEFF2 0x0CD4 + +/** + * Calculate LPC coefficients based on cutoff frequency and sample rate. + * + * @param cutoff cutoff frequency + * @param sample_rate sample rate + * @param bits number of bits used to quantize coefficients + * @param[out] coeff 2 quantized LPC coefficients + */ +void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff); #endif /* AVCODEC_ADX_H */ 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; } diff --git a/libavcodec/adxenc.c b/libavcodec/adxenc.c index 7225c3159d..b85a70d7b2 100644 --- a/libavcodec/adxenc.c +++ b/libavcodec/adxenc.c @@ -34,7 +34,7 @@ /* 18 bytes <-> 32 samples */ -static void adx_encode(unsigned char *adx,const short *wav, +static void adx_encode(ADXContext *c, unsigned char *adx, const short *wav, ADXChannelState *prev) { int scale; @@ -48,7 +48,7 @@ static void adx_encode(unsigned char *adx,const short *wav, s2 = prev->s2; for(i=0;i<32;i++) { s0 = wav[i]; - d = ((s0 << COEFF_BITS) - COEFF1 * s1 + COEFF2 * s2) >> COEFF_BITS; + d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS; data[i]=d; if (max<d) max=d; if (min>d) min=d; @@ -102,19 +102,24 @@ static int adx_encode_header(AVCodecContext *avctx,unsigned char *buf,size_t buf } adxhdr; /* big endian */ /* offset-6 "(c)CRI" */ #endif + ADXContext *c = avctx->priv_data; + AV_WB32(buf+0x00,0x80000000|0x20); AV_WB32(buf+0x04,0x03120400|avctx->channels); AV_WB32(buf+0x08,avctx->sample_rate); AV_WB32(buf+0x0c,0); /* FIXME: set after */ - AV_WB32(buf+0x10,0x01040300); - AV_WB32(buf+0x14,0x00000000); - AV_WB32(buf+0x18,0x00000000); - memcpy(buf+0x1c,"\0\0(c)CRI",8); + AV_WB16(buf + 0x10, c->cutoff); + AV_WB32(buf + 0x12, 0x03000000); + AV_WB32(buf + 0x16, 0x00000000); + AV_WB32(buf + 0x1a, 0x00000000); + memcpy (buf + 0x1e, "(c)CRI", 6); return 0x20+4; } static av_cold int adx_encode_init(AVCodecContext *avctx) { + ADXContext *c = avctx->priv_data; + if (avctx->channels > 2) return -1; /* only stereo or mono =) */ avctx->frame_size = 32; @@ -124,6 +129,10 @@ static av_cold int adx_encode_init(AVCodecContext *avctx) // avctx->bit_rate = avctx->sample_rate*avctx->channels*18*8/32; + /* the cutoff can be adjusted, but this seems to work pretty well */ + c->cutoff = 500; + ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff); + av_log(avctx, AV_LOG_DEBUG, "adx encode init\n"); return 0; @@ -159,7 +168,7 @@ static int adx_encode_frame(AVCodecContext *avctx, if (avctx->channels==1) { while(rest>=32) { - adx_encode(dst,samples,c->prev); + adx_encode(c, dst, samples, c->prev); dst+=18; samples+=32; rest-=32; @@ -174,8 +183,8 @@ static int adx_encode_frame(AVCodecContext *avctx, tmpbuf[i+32] = samples[i*2+1]; } - adx_encode(dst,tmpbuf,c->prev); - adx_encode(dst+18,tmpbuf+32,c->prev+1); + adx_encode(c, dst, tmpbuf, c->prev); + adx_encode(c, dst + 18, tmpbuf + 32, c->prev + 1); dst+=18*2; samples+=32*2; rest-=32*2; |