From b11edbd289e454a173914049ae4643a5498520d9 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 19 Feb 2015 22:49:57 +0100 Subject: [PATCH] avcodec/dss_sp: Avoid a slow division and modulo in the pitch_lag calculation Also check the combined_pitch for validity (which is needed to keep the behavior identical in the error case) Signed-off-by: Michael Niedermayer --- libavcodec/dss_sp.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/libavcodec/dss_sp.c b/libavcodec/dss_sp.c index 462418bca4..42ba1c42c2 100644 --- a/libavcodec/dss_sp.c +++ b/libavcodec/dss_sp.c @@ -50,6 +50,7 @@ typedef struct DssSpFrame { } DssSpFrame; typedef struct DssSpContext { + AVCodecContext *avctx; int32_t excitation[288 + 6]; int32_t history[187]; DssSpFrame fparam; @@ -296,6 +297,7 @@ static av_cold int dss_sp_decode_init(AVCodecContext *avctx) memset(p->history, 0, sizeof(p->history)); p->pulse_dec_mode = 1; + p->avctx = avctx; return 0; } @@ -400,10 +402,15 @@ static void dss_sp_unpack_coeffs(DssSpContext *p, const uint8_t *src) combined_pitch /= 151; - for (i = 1; i < SUBFRAMES; i++) { + for (i = 1; i < SUBFRAMES - 1; i++) { fparam->pitch_lag[i] = combined_pitch % 48; combined_pitch /= 48; } + if (combined_pitch > 47) { + av_log (p->avctx, AV_LOG_WARNING, "combined_pitch was too large\n"); + combined_pitch = 0; + } + fparam->pitch_lag[i] = combined_pitch; pitch_lag = fparam->pitch_lag[0]; for (i = 1; i < SUBFRAMES; i++) {