diff options
Diffstat (limited to 'libavcodec/g726.c')
-rw-r--r-- | libavcodec/g726.c | 98 |
1 files changed, 49 insertions, 49 deletions
diff --git a/libavcodec/g726.c b/libavcodec/g726.c index efc3c5faef..57b5e713ae 100644 --- a/libavcodec/g726.c +++ b/libavcodec/g726.c @@ -1,9 +1,9 @@ /* - * G.726 ADPCM audio codec + * G.726 ADPCM audio codec * Copyright (c) 2004 Roman Shaposhnik. * * This is a very straightforward rendition of the G.726 - * Section 4 "Computational Details". + * Section 4 "Computational Details". * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -26,7 +26,7 @@ /** * G.726 11bit float. - * G.726 Standard uses rather odd 11bit floating point arithmentic for + * G.726 Standard uses rather odd 11bit floating point arithmentic for * numerous occasions. It's a mistery to me why they did it this way * instead of simply using 32bit integer arithmetic. */ @@ -42,7 +42,7 @@ static inline Float11* i2f(int16_t i, Float11* f) if (f->sign) i = -i; f->exp = av_log2_16bit(i) + !!i; - f->mant = i? (i<<6) >> f->exp : + f->mant = i? (i<<6) >> f->exp : 1<<5; return f; } @@ -72,13 +72,13 @@ typedef struct G726Tables { typedef struct G726Context { G726Tables* tbls; /**< static tables needed for computation */ - + Float11 sr[2]; /**< prev. reconstructed samples */ Float11 dq[6]; /**< prev. difference */ int a[2]; /**< second order predictor coeffs */ int b[6]; /**< sixth order predictor coeffs */ int pk[2]; /**< signs of prev. 2 sez + dq */ - + int ap; /**< scale factor control */ int yu; /**< fast scale factor */ int yl; /**< slow scale factor */ @@ -92,65 +92,65 @@ typedef struct G726Context { } G726Context; static int quant_tbl16[] = /**< 16kbit/s 2bits per sample */ - { 260, INT_MAX }; + { 260, INT_MAX }; static int iquant_tbl16[] = { 116, 365, 365, 116 }; -static int W_tbl16[] = +static int W_tbl16[] = { -22, 439, 439, -22 }; static int F_tbl16[] = { 0, 7, 7, 0 }; - + static int quant_tbl24[] = /**< 24kbit/s 3bits per sample */ { 7, 217, 330, INT_MAX }; static int iquant_tbl24[] = { INT_MIN, 135, 273, 373, 373, 273, 135, INT_MIN }; -static int W_tbl24[] = - { -4, 30, 137, 582, 582, 137, 30, -4 }; +static int W_tbl24[] = + { -4, 30, 137, 582, 582, 137, 30, -4 }; static int F_tbl24[] = { 0, 1, 2, 7, 7, 2, 1, 0 }; - + static int quant_tbl32[] = /**< 32kbit/s 4bits per sample */ { -125, 79, 177, 245, 299, 348, 399, INT_MAX }; static int iquant_tbl32[] = - { INT_MIN, 4, 135, 213, 273, 323, 373, 425, + { INT_MIN, 4, 135, 213, 273, 323, 373, 425, 425, 373, 323, 273, 213, 135, 4, INT_MIN }; -static int W_tbl32[] = +static int W_tbl32[] = { -12, 18, 41, 64, 112, 198, 355, 1122, 1122, 355, 198, 112, 64, 41, 18, -12}; -static int F_tbl32[] = +static int F_tbl32[] = { 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 }; - + static int quant_tbl40[] = /**< 40kbit/s 5bits per sample */ { -122, -16, 67, 138, 197, 249, 297, 338, 377, 412, 444, 474, 501, 527, 552, INT_MAX }; static int iquant_tbl40[] = - { INT_MIN, -66, 28, 104, 169, 224, 274, 318, + { INT_MIN, -66, 28, 104, 169, 224, 274, 318, 358, 395, 429, 459, 488, 514, 539, 566, 566, 539, 514, 488, 459, 429, 395, 358, 318, 274, 224, 169, 104, 28, -66, INT_MIN }; -static int W_tbl40[] = +static int W_tbl40[] = { 14, 14, 24, 39, 40, 41, 58, 100, - 141, 179, 219, 280, 358, 440, 529, 696, + 141, 179, 219, 280, 358, 440, 529, 696, 696, 529, 440, 358, 280, 219, 179, 141, 100, 58, 41, 40, 39, 24, 14, 14 }; -static int F_tbl40[] = +static int F_tbl40[] = { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6, 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 }; -static G726Tables G726Tables_pool[] = +static G726Tables G726Tables_pool[] = {{ 2, quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 }, { 3, quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 }, { 4, quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 }, { 5, quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }}; - + /** - * Para 4.2.2 page 18: Adaptive quantizer. + * Para 4.2.2 page 18: Adaptive quantizer. */ static inline uint8_t quant(G726Context* c, int d) { int sign, exp, i, dln; - + sign = i = 0; if (d < 0) { sign = 1; @@ -158,16 +158,16 @@ static inline uint8_t quant(G726Context* c, int d) } exp = av_log2_16bit(d); dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2); - + while (c->tbls->quant[i] < INT_MAX && c->tbls->quant[i] < dln) ++i; - + if (sign) i = ~i; if (c->tbls->bits != 2 && i == 0) /* I'm not sure this is a good idea */ i = 0xff; - return i; + return i; } /** @@ -176,18 +176,18 @@ static inline uint8_t quant(G726Context* c, int d) static inline int16_t inverse_quant(G726Context* c, int i) { int dql, dex, dqt; - + dql = c->tbls->iquant[i] + (c->y >> 2); dex = (dql>>7) & 0xf; /* 4bit exponent */ dqt = (1<<7) + (dql & 0x7f); /* log2 -> linear */ - return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex)); + return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex)); } static inline int16_t g726_iterate(G726Context* c, int16_t I) { int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0; Float11 f; - + dq = inverse_quant(c, I); if (I >> (c->tbls->bits - 1)) /* get the sign */ dq = -dq; @@ -201,7 +201,7 @@ static inline int16_t g726_iterate(G726Context* c, int16_t I) tr = 1; else tr = 0; - + /* Update second order predictor coefficient A2 and A1 */ pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0; dq0 = dq ? sgn(dq) : 0; @@ -213,7 +213,7 @@ static inline int16_t g726_iterate(G726Context* c, int16_t I) } else { /* This is a bit crazy, but it really is +255 not +256 */ fa1 = clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255); - + c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7); c->a[1] = clip(c->a[1], -12288, 12288); c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8); @@ -232,28 +232,28 @@ static inline int16_t g726_iterate(G726Context* c, int16_t I) c->dq[i] = c->dq[i-1]; i2f(dq, &c->dq[0]); c->dq[0].sign = I >> (c->tbls->bits - 1); /* Isn't it crazy ?!?! */ - + /* Update tone detect [I'm not sure 'tr == 0' is really needed] */ - c->td = (tr == 0 && c->a[1] < -11776); - + c->td = (tr == 0 && c->a[1] < -11776); + /* Update Ap */ c->dms += ((c->tbls->F[I]<<9) - c->dms) >> 5; c->dml += ((c->tbls->F[I]<<11) - c->dml) >> 7; - if (tr) + if (tr) c->ap = 256; else if (c->y > 1535 && !c->td && (abs((c->dms << 2) - c->dml) < (c->dml >> 3))) c->ap += (-c->ap) >> 4; else - c->ap += (0x200 - c->ap) >> 4; + c->ap += (0x200 - c->ap) >> 4; /* Update Yu and Yl */ c->yu = clip(c->y + (((c->tbls->W[I] << 5) - c->y) >> 5), 544, 5120); c->yl += c->yu + ((-c->yl)>>6); - + /* Next iteration for Y */ al = (c->ap >= 256) ? 1<<6 : c->ap >> 2; c->y = (c->yl + (c->yu - (c->yl>>6))*al) >> 6; - + /* Next iteration for SE and SEZ */ c->se = 0; for (i=0; i<6; i++) @@ -302,7 +302,7 @@ static int16_t g726_decode(G726Context* c, int16_t i) static int16_t g726_encode(G726Context* c, int16_t sig) { uint8_t i; - + i = quant(c, sig/4 - c->se) & ((1<<c->tbls->bits) - 1); g726_iterate(c, i); return i; @@ -320,7 +320,7 @@ typedef struct AVG726Context { static int g726_init(AVCodecContext * avctx) { AVG726Context* c = (AVG726Context*)avctx->priv_data; - + if (avctx->channels != 1 || (avctx->bit_rate != 16000 && avctx->bit_rate != 24000 && avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) { @@ -364,8 +364,8 @@ static int g726_encode_frame(AVCodecContext *avctx, flush_put_bits(&pb); - return put_bits_count(&pb)>>3; -} + return put_bits_count(&pb)>>3; +} static int g726_decode_frame(AVCodecContext *avctx, void *data, int *data_size, @@ -375,11 +375,11 @@ static int g726_decode_frame(AVCodecContext *avctx, short *samples = data; uint8_t code; uint8_t mask; - GetBitContext gb; - + GetBitContext gb; + if (!buf_size) goto out; - + mask = (1<<c->code_size) - 1; init_get_bits(&gb, buf, buf_size * 8); if (c->bits_left) { @@ -387,13 +387,13 @@ static int g726_decode_frame(AVCodecContext *avctx, code = (c->bit_buffer << s) | get_bits(&gb, s); *samples++ = g726_decode(&c->c, code & mask); } - + while (get_bits_count(&gb) + c->code_size <= buf_size*8) *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size) & mask); - + c->bits_left = buf_size*8 - get_bits_count(&gb); c->bit_buffer = get_bits(&gb, c->bits_left); - + out: *data_size = (uint8_t*)samples - (uint8_t*)data; return buf_size; |