From 0a0a10f358345f749e4a05021301461994f1ffc5 Mon Sep 17 00:00:00 2001 From: Josh Coalson Date: Sat, 31 Mar 2007 01:01:02 +0000 Subject: [PATCH] minor optimizations to precompute_partition_info_sums_() --- src/libFLAC/stream_encoder.c | 67 +++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 32 deletions(-) diff --git a/src/libFLAC/stream_encoder.c b/src/libFLAC/stream_encoder.c index 76173f0..5b2c12a 100644 --- a/src/libFLAC/stream_encoder.c +++ b/src/libFLAC/stream_encoder.c @@ -249,6 +249,7 @@ static unsigned find_best_partition_order_( unsigned rice_parameter, unsigned min_partition_order, unsigned max_partition_order, + unsigned bps, FLAC__bool do_escape_coding, unsigned rice_parameter_search_dist, FLAC__EntropyCodingMethod_PartitionedRice *best_partitioned_rice @@ -260,7 +261,8 @@ static void precompute_partition_info_sums_( unsigned residual_samples, unsigned predictor_order, unsigned min_partition_order, - unsigned max_partition_order + unsigned max_partition_order, + unsigned bps ); static void precompute_partition_info_escapes_( @@ -3741,6 +3743,7 @@ unsigned evaluate_fixed_subframe_( rice_parameter, min_partition_order, max_partition_order, + subframe_bps, do_escape_coding, rice_parameter_search_dist, &subframe->data.fixed.entropy_coding_method.data.partitioned_rice @@ -3821,6 +3824,7 @@ unsigned evaluate_lpc_subframe_( rice_parameter, min_partition_order, max_partition_order, + subframe_bps, do_escape_coding, rice_parameter_search_dist, &subframe->data.lpc.entropy_coding_method.data.partitioned_rice @@ -3878,6 +3882,7 @@ unsigned find_best_partition_order_( unsigned rice_parameter, unsigned min_partition_order, unsigned max_partition_order, + unsigned bps, FLAC__bool do_escape_coding, unsigned rice_parameter_search_dist, FLAC__EntropyCodingMethod_PartitionedRice *best_partitioned_rice @@ -3890,7 +3895,7 @@ unsigned find_best_partition_order_( max_partition_order = FLAC__format_get_max_rice_partition_order_from_blocksize_limited_max_and_predictor_order(max_partition_order, blocksize, predictor_order); min_partition_order = min(min_partition_order, max_partition_order); - precompute_partition_info_sums_(residual, abs_residual_partition_sums, residual_samples, predictor_order, min_partition_order, max_partition_order); + precompute_partition_info_sums_(residual, abs_residual_partition_sums, residual_samples, predictor_order, min_partition_order, max_partition_order, bps); if(do_escape_coding) precompute_partition_info_escapes_(residual, raw_bits_per_partition, residual_samples, predictor_order, min_partition_order, max_partition_order); @@ -3950,56 +3955,54 @@ void precompute_partition_info_sums_( unsigned residual_samples, unsigned predictor_order, unsigned min_partition_order, - unsigned max_partition_order + unsigned max_partition_order, + unsigned bps ) { int partition_order; unsigned from_partition, to_partition = 0; const unsigned blocksize = residual_samples + predictor_order; + const unsigned partitions = 1u << max_partition_order; + const unsigned default_partition_samples = blocksize >> max_partition_order; + unsigned partition, end, residual_sample; + + FLAC__ASSERT(default_partition_samples > predictor_order); /* first do max_partition_order */ - for(partition_order = (int)max_partition_order; partition_order >= 0; partition_order--) { - FLAC__uint64 abs_residual_partition_sum; /* OPT: can reasonably be FLAC__uint32 for bps <= 17 and maybe higher */ - unsigned partition, partition_sample, partition_samples, residual_sample; - const unsigned partitions = 1u << partition_order; - const unsigned default_partition_samples = blocksize >> partition_order; + if(FLAC__bitmath_ilog2(default_partition_samples) + bps < 32) { /* very slightly pessimistic but still catches all common cases */ + FLAC__uint32 abs_residual_partition_sum; - FLAC__ASSERT(default_partition_samples > predictor_order); + end = (unsigned)(-(int)predictor_order); + for(partition = residual_sample = 0; partition < partitions; partition++) { + end += default_partition_samples; + abs_residual_partition_sum = 0; + for( ; residual_sample < end; residual_sample++) + abs_residual_partition_sum += abs(residual[residual_sample]); /* abs(INT_MIN) is undefined, but if the residual is INT_MIN we have bigger problems */ + abs_residual_partition_sums[partition] = abs_residual_partition_sum; + } + } + else { /* have to pessimistically use 64 bits for accumulator */ + FLAC__uint64 abs_residual_partition_sum; + end = (unsigned)(-(int)predictor_order); for(partition = residual_sample = 0; partition < partitions; partition++) { - partition_samples = default_partition_samples; - if(partition == 0) - partition_samples -= predictor_order; + end += default_partition_samples; abs_residual_partition_sum = 0; - for(partition_sample = 0; partition_sample < partition_samples; partition_sample++, residual_sample++) { -#if defined _MSC_VER - /* OPT: abs() may be faster for some compilers */ + for( ; residual_sample < end; residual_sample++) abs_residual_partition_sum += abs(residual[residual_sample]); /* abs(INT_MIN) is undefined, but if the residual is INT_MIN we have bigger problems */ -#else - const FLAC__int32 r = residual[residual_sample]; - if(r < 0) - abs_residual_partition_sum -= r; - else - abs_residual_partition_sum += r; -#endif - } abs_residual_partition_sums[partition] = abs_residual_partition_sum; } - to_partition = partitions; - break; } /* now merge partitions for lower orders */ - for(from_partition = 0, --partition_order; partition_order >= (int)min_partition_order; partition_order--) { - FLAC__uint64 s; + for(from_partition = 0, to_partition = partitions, partition_order = (int)max_partition_order - 1; partition_order >= (int)min_partition_order; partition_order--) { unsigned i; const unsigned partitions = 1u << partition_order; for(i = 0; i < partitions; i++) { - s = abs_residual_partition_sums[from_partition]; - from_partition++; - abs_residual_partition_sums[to_partition] = s + abs_residual_partition_sums[from_partition]; - from_partition++; - to_partition++; + abs_residual_partition_sums[to_partition++] = + abs_residual_partition_sums[from_partition ] + + abs_residual_partition_sums[from_partition+1]; + from_partition += 2; } } } -- 2.7.4