From 08e82e5b572b440f4faf160d2eac923ca47a59f8 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 3 May 2022 18:30:59 +0200 Subject: [PATCH] avcodec/smacker: Optimize constant 16bit audio output MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Reviewed-by: Paul B Mahol Reviewed-by: Tomas Härdin Signed-off-by: Michael Niedermayer --- libavcodec/smacker.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/libavcodec/smacker.c b/libavcodec/smacker.c index 179c70f1ee..5d94a54179 100644 --- a/libavcodec/smacker.c +++ b/libavcodec/smacker.c @@ -601,7 +601,7 @@ static int smka_decode_frame(AVCodecContext *avctx, AVFrame *frame, int i, res, ret; int unp_size; int bits, stereo; - unsigned pred[2], val; + unsigned pred[2], val, val2; if (buf_size <= 4) { av_log(avctx, AV_LOG_ERROR, "packet is too small\n"); @@ -672,7 +672,11 @@ static int smka_decode_frame(AVCodecContext *avctx, AVFrame *frame, pred[i] = av_bswap16(get_bits(&gb, 16)); for(i = 0; i <= stereo; i++) *samples++ = pred[i]; - for(; i < unp_size / 2; i++) { + unp_size /= 2; + + if (vlc[0 ].table || vlc[ 1].table || + vlc[2*stereo].table || vlc[2*stereo+1].table) { + for(; i < unp_size ; i++) { unsigned idx = 2 * (i & stereo); if (get_bits_left(&gb) < 0) { ret = AVERROR_INVALIDDATA; @@ -691,6 +695,22 @@ static int smka_decode_frame(AVCodecContext *avctx, AVFrame *frame, pred[idx / 2] += val; *samples++ = pred[idx / 2]; } + } else if (stereo) { + val = 256*values[1] + values[0]; + val2 = 256*values[3] + values[2]; + for(; i < unp_size; i+=2) { + pred[0] += val; + pred[1] += val2; + *samples++ = pred[0]; + *samples++ = pred[1]; + } + } else { + val = 256*values[1] + values[0]; + for(; i < unp_size; i++) { + pred[0] += val; + *samples++ = pred[0]; + } + } } else { //8-bit data for(i = stereo; i >= 0; i--) pred[i] = get_bits(&gb, 8);