From de0b586a87c510685bd9a32ca832007c422d7cd8 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Thu, 8 Sep 2011 16:03:44 -0400 Subject: [PATCH] adpcm: simplify and speed up several ADPCM decoders. --- libavcodec/adpcm.c | 86 +++++++++++----------------------------------- 1 file changed, 21 insertions(+), 65 deletions(-) diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c index 25432f6160..c6b0aaa399 100644 --- a/libavcodec/adpcm.c +++ b/libavcodec/adpcm.c @@ -527,21 +527,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx, *samples++ = c->status[1].predictor; } while (src < buf + buf_size) { - - /* take care of the top nibble (always left or mono channel) */ - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] >> 4, 3); - - /* take care of the bottom nibble, which is right sample for - * stereo, or another mono sample */ - if (st) - *samples++ = adpcm_ima_expand_nibble(&c->status[1], - src[0] & 0x0F, 3); - else - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] & 0x0F, 3); - - src++; + uint8_t v = *src++; + *samples++ = adpcm_ima_expand_nibble(&c->status[0 ], v >> 4 , 3); + *samples++ = adpcm_ima_expand_nibble(&c->status[st], v & 0x0F, 3); } break; case CODEC_ID_ADPCM_IMA_DK3: @@ -600,39 +588,25 @@ static int adpcm_decode_frame(AVCodecContext *avctx, } while (src < buf + buf_size) { - + uint8_t v1, v2; + uint8_t v = *src++; + /* nibbles are swapped for mono */ if (st) { - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] >> 4 , 3); - *samples++ = adpcm_ima_expand_nibble(&c->status[1], - src[0] & 0x0F, 3); + v1 = v >> 4; + v2 = v & 0x0F; } else { - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] & 0x0F, 3); - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] >> 4 , 3); + v2 = v >> 4; + v1 = v & 0x0F; } - - src++; + *samples++ = adpcm_ima_expand_nibble(&c->status[0 ], v1, 3); + *samples++ = adpcm_ima_expand_nibble(&c->status[st], v2, 3); } break; case CODEC_ID_ADPCM_IMA_WS: - /* no per-block initialization; just start decoding the data */ while (src < buf + buf_size) { - - if (st) { - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] >> 4 , 3); - *samples++ = adpcm_ima_expand_nibble(&c->status[1], - src[0] & 0x0F, 3); - } else { - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] >> 4 , 3); - *samples++ = adpcm_ima_expand_nibble(&c->status[0], - src[0] & 0x0F, 3); - } - - src++; + uint8_t v = *src++; + *samples++ = adpcm_ima_expand_nibble(&c->status[0], v >> 4 , 3); + *samples++ = adpcm_ima_expand_nibble(&c->status[st], v & 0x0F, 3); } break; case CODEC_ID_ADPCM_XA: @@ -886,18 +860,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx, break; case CODEC_ID_ADPCM_CT: while (src < buf + buf_size) { - if (st) { - *samples++ = adpcm_ct_expand_nibble(&c->status[0], - src[0] >> 4); - *samples++ = adpcm_ct_expand_nibble(&c->status[1], - src[0] & 0x0F); - } else { - *samples++ = adpcm_ct_expand_nibble(&c->status[0], - src[0] >> 4); - *samples++ = adpcm_ct_expand_nibble(&c->status[0], - src[0] & 0x0F); - } - src++; + uint8_t v = *src++; + *samples++ = adpcm_ct_expand_nibble(&c->status[0 ], v >> 4 ); + *samples++ = adpcm_ct_expand_nibble(&c->status[st], v & 0x0F); } break; case CODEC_ID_ADPCM_SBPRO_4: @@ -1005,18 +970,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx, } case CODEC_ID_ADPCM_YAMAHA: while (src < buf + buf_size) { - if (st) { - *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], - src[0] & 0x0F); - *samples++ = adpcm_yamaha_expand_nibble(&c->status[1], - src[0] >> 4 ); - } else { - *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], - src[0] & 0x0F); - *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], - src[0] >> 4 ); - } - src++; + uint8_t v = *src++; + *samples++ = adpcm_yamaha_expand_nibble(&c->status[0 ], v & 0x0F); + *samples++ = adpcm_yamaha_expand_nibble(&c->status[st], v >> 4 ); } break; case CODEC_ID_ADPCM_THP: