From dbb45a3bb74880ee540591e936ebe1d354d0a855 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 16 Jul 2006 15:46:45 +0000 Subject: [PATCH] log prediction order search method Originally committed as revision 5763 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/flacenc.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/libavcodec/flacenc.c b/libavcodec/flacenc.c index da46533..9451340 100644 --- a/libavcodec/flacenc.c +++ b/libavcodec/flacenc.c @@ -43,6 +43,7 @@ #define ORDER_METHOD_4LEVEL 2 #define ORDER_METHOD_8LEVEL 3 #define ORDER_METHOD_SEARCH 4 +#define ORDER_METHOD_LOG 5 #define FLAC_STREAMINFO_SIZE 34 @@ -291,7 +292,7 @@ static int flac_encode_init(AVCodecContext *avctx) s->options.min_prediction_order, s->options.max_prediction_order); if(avctx->prediction_order_method >= 0) { - if(avctx->prediction_order_method > ORDER_METHOD_SEARCH) { + if(avctx->prediction_order_method > ORDER_METHOD_LOG) { av_log(avctx, AV_LOG_ERROR, "invalid prediction order method: %d\n", avctx->prediction_order_method); return -1; @@ -309,6 +310,8 @@ static int flac_encode_init(AVCodecContext *avctx) "8-level"); break; case ORDER_METHOD_SEARCH: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", "full search"); break; + case ORDER_METHOD_LOG: av_log(avctx, AV_LOG_DEBUG, " order method: %s\n", + "log search"); break; } if(avctx->min_partition_order >= 0) { @@ -951,6 +954,26 @@ static int encode_residual(FlacEncodeContext *ctx, int ch) } } opt_order++; + } else if(omethod == ORDER_METHOD_LOG) { + uint32_t bits[MAX_LPC_ORDER]; + int step; + + opt_order= min_order - 1 + (max_order-min_order)/3; + memset(bits, -1, sizeof(bits)); + + for(step=16 ;step; step>>=1){ + int last= opt_order; + for(i=last-step; i<=last+step; i+= step){ + if(i=max_order || bits[i] < UINT32_MAX) + continue; + encode_residual_lpc(res, smp, n, i+1, coefs[i], shift[i]); + bits[i] = calc_rice_params_lpc(&sub->rc, min_porder, max_porder, + res, n, i+1, sub->obits, precision); + if(bits[i] < bits[opt_order]) + opt_order= i; + } + } + opt_order++; } sub->order = opt_order; -- 2.7.4