On Mon, Jan 24, 2005 at 06:31:21PM -0800, Josh Coalson wrote: > yes, a mere 2 years later it is checked in! > > speed improvement for me is roughly 17% testing flac files on > linux-i386.
Thanks! In case you would like to check another old patch, I have attached updated patch for seekable stream decoder, originally posted on 09/07/2003. -- Miroslav Lichvar
--- seekable_stream_decoder.c.orig 2005-01-25 05:18:31.000000000 +0100 +++ seekable_stream_decoder.c 2005-01-25 23:39:03.000000000 +0100 @@ -857,11 +857,11 @@ FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample) { - FLAC__uint64 first_frame_offset, lower_bound, upper_bound; - FLAC__int64 pos = -1, last_pos = -1; - int i, lower_seek_point = -1, upper_seek_point = -1; + FLAC__uint64 first_frame_offset, lower_bound, upper_bound, lower_bound_sample, upper_bound_sample; + FLAC__int64 pos, last_pos = -1; + int i; unsigned approx_bytes_per_frame; - FLAC__uint64 last_frame_sample = FLAC__U64L(0xffffffffffffffff); + FLAC__uint64 last_frame_sample = FLAC__U64L(0xffffffffffffffff), this_frame_sample; FLAC__bool needs_seek; const FLAC__uint64 total_samples = decoder->private_->stream_info.total_samples; const unsigned min_blocksize = decoder->private_->stream_info.min_blocksize; @@ -903,12 +903,14 @@ * the first and last frames. */ lower_bound = first_frame_offset; + lower_bound_sample = 0; /* calc the upper_bound, beyond which we never want to seek */ if(max_framesize > 0) upper_bound = stream_length - (max_framesize + 128 + 2); /* 128 for a possible ID3V1 tag, 2 for indexing differences */ else upper_bound = stream_length - ((channels * bps * FLAC__MAX_BLOCK_SIZE) / 8 + 128 + 2); + upper_bound_sample = total_samples > 0 ? total_samples : target_sample; /* * Now we refine the bounds if we have a seektable with @@ -923,7 +925,7 @@ } if(i >= 0) { /* i.e. we found a suitable seek point... */ lower_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset; - lower_seek_point = i; + lower_bound_sample = decoder->private_->seek_table->points[i].sample_number; } /* find the closest seek point > target_sample, if it exists */ @@ -933,98 +935,33 @@ } if(i < (int)decoder->private_->seek_table->num_points) { /* i.e. we found a suitable seek point... */ upper_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset; - upper_seek_point = i; + upper_bound_sample = decoder->private_->seek_table->points[i].sample_number; } } - /* - * Now guess at where within those bounds our target - * sample will be. - */ - if(lower_seek_point >= 0) { - /* first see if our sample is within a few frames of the lower seekpoint */ - if(decoder->private_->seek_table->points[lower_seek_point].sample_number <= target_sample && target_sample < decoder->private_->seek_table->points[lower_seek_point].sample_number + (decoder->private_->seek_table->points[lower_seek_point].frame_samples * 4)) { - pos = (FLAC__int64)lower_bound; - } - else if(upper_seek_point >= 0) { - const FLAC__uint64 target_offset = target_sample - decoder->private_->seek_table->points[lower_seek_point].sample_number; - const FLAC__uint64 range_samples = decoder->private_->seek_table->points[upper_seek_point].sample_number - decoder->private_->seek_table->points[lower_seek_point].sample_number; - const FLAC__uint64 range_bytes = (upper_bound>lower_bound? upper_bound - lower_bound - 1 : 0); + decoder->private_->target_sample = target_sample; + + needs_seek = true; + while(1) { + if(needs_seek) { #ifndef FLAC__INTEGER_ONLY_LIBRARY #if defined _MSC_VER || defined __MINGW32__ /* with MSVC you have to spoon feed it the casting */ - pos = (FLAC__int64)lower_bound + (FLAC__int64)(((FLAC__double)(FLAC__int64)target_offset / (FLAC__double)(FLAC__int64)range_samples) * (FLAC__double)(FLAC__int64)(range_bytes-1)) - approx_bytes_per_frame; + pos = (FLAC__int64)lower_bound + (FLAC__int64)(((FLAC__double)(FLAC__int64)(target_sample - lower_bound_sample) / (FLAC__double)(FLAC__int64)(upper_bound_sample - lower_bound_sample)) * (FLAC__double)(FLAC__int64)(upper_bound - lower_bound)) - approx_bytes_per_frame; #else - pos = (FLAC__int64)lower_bound + (FLAC__int64)(((FLAC__double)target_offset / (FLAC__double)range_samples) * (FLAC__double)range_bytes) - approx_bytes_per_frame; + pos = (FLAC__int64)lower_bound + (FLAC__int64)(((FLAC__double)(target_sample - lower_bound_sample) / (FLAC__double)(upper_bound_sample - lower_bound_sample)) * (FLAC__double)(upper_bound - lower_bound)) - approx_bytes_per_frame; #endif #else /* a little less accurate: */ - if (range_bytes <= 0xffffffff) - pos = (FLAC__int64)lower_bound + (FLAC__int64)((target_offset * range_bytes) / range_samples) - approx_bytes_per_frame; + if (upper_bound - lower_bound < 0xffffffff) + pos = (FLAC__int64)lower_bound + (FLAC__int64)((target_sample - lower_bound_sample) * (upper_bound - lower_bound) / (upper_bound_sample - lower_bound_sample)) - approx_bytes_per_frame; else /* @@@ WATCHOUT, ~2TB limit */ - pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_offset>>8) * (range_bytes>>8)) / (range_samples>>16)) - approx_bytes_per_frame; + pos = (FLAC__int64)lower_bound + (FLAC__int64)(((target_sample - lower_bound_sample >> 8) * (upper_bound - lower_bound >> 8)) / (upper_bound_sample - lower_bound_sample >> 16)) - approx_bytes_per_frame; #endif - } - } - - /* - * If there's no seek table, we need to use the metadata (if we - * have it) and the filelength to estimate the position of the - * frame with the correct sample. - */ - if(pos < 0 && total_samples > 0) { - /* - * For max accuracy we should be using - * (stream_length-first_frame_offset-1) in the divisor, but the - * difference is trivial and (stream_length-first_frame_offset) - * has no chance of underflow. - */ -#ifndef FLAC__INTEGER_ONLY_LIBRARY -#if defined _MSC_VER || defined __MINGW32__ - /* with VC++ you have to spoon feed it the casting */ - pos = (FLAC__int64)first_frame_offset + (FLAC__int64)(((FLAC__double)(FLAC__int64)target_sample / (FLAC__double)(FLAC__int64)total_samples) * (FLAC__double)(FLAC__int64)(stream_length-first_frame_offset)) - approx_bytes_per_frame; -#else - pos = (FLAC__int64)first_frame_offset + (FLAC__int64)(((FLAC__double)target_sample / (FLAC__double)total_samples) * (FLAC__double)(stream_length-first_frame_offset)) - approx_bytes_per_frame; -#endif -#else - /* a little less accurate: */ - if (stream_length < 0xffffffff) - pos = (FLAC__int64)first_frame_offset + (FLAC__int64)((target_sample * (stream_length-first_frame_offset)) / total_samples) - approx_bytes_per_frame; - else /* @@@ WATCHOUT, ~2TB limit */ - pos = (FLAC__int64)first_frame_offset + (FLAC__int64)(((target_sample>>8) * ((stream_length-first_frame_offset)>>8)) / (total_samples>>16)) - approx_bytes_per_frame; -#endif - } - - /* - * If there's no seek table and total_samples is unknown, we - * don't even bother trying to figure out a target, we just use - * our current position. - */ - if(pos < 0) { - FLAC__uint64 upos; - if(decoder->private_->tell_callback(decoder, &upos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) { - decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; - return false; - } - pos = (FLAC__int64)upos; - needs_seek = false; - } - else - needs_seek = true; - - /* clip the position to the bounds, lower bound takes precedence */ - if(pos >= (FLAC__int64)upper_bound) { - pos = (FLAC__int64)upper_bound-1; - needs_seek = true; - } - if(pos < (FLAC__int64)lower_bound) { - pos = (FLAC__int64)lower_bound; - needs_seek = true; - } - - decoder->private_->target_sample = target_sample; - while(1) { - if(needs_seek) { + if(pos >= (FLAC__int64)upper_bound) + pos = (FLAC__int64)upper_bound - 1; + if(pos < (FLAC__int64)lower_bound) + pos = (FLAC__int64)lower_bound; if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) { decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; return false; @@ -1065,45 +1002,43 @@ if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING) { break; } - else { /* we need to narrow the search */ - const FLAC__uint64 this_frame_sample = decoder->private_->last_frame.header.number.sample_number; - FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER); - if(this_frame_sample == last_frame_sample && pos < last_pos) { - /* our last move backwards wasn't big enough, double it */ - pos -= (last_pos - pos); - needs_seek = true; + /* we need to narrow the search */ + this_frame_sample = decoder->private_->last_frame.header.number.sample_number; + FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER); + + approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * channels * bps/8 + 64; + + if(target_sample < this_frame_sample) { + if(this_frame_sample == last_frame_sample) { + /* our last move backwards wasn't big enough */ + upper_bound -= approx_bytes_per_frame; } else { - if(target_sample < this_frame_sample) { - last_pos = pos; - approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * channels * bps/8 + 64; - pos -= approx_bytes_per_frame; - needs_seek = true; - } - else { /* target_sample >= this_frame_sample + this frame's blocksize */ - FLAC__uint64 upos; - if(decoder->private_->tell_callback(decoder, &upos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) { - decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; - return false; - } - last_pos = pos; - pos = (FLAC__int64)upos; - pos -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder); - needs_seek = false; - /* - * if we haven't hit the target frame yet and our position hasn't changed, - * it means we're at the end of the stream and the seek target does not exist. - */ - if(last_pos == pos) { - decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; - return false; - } + upper_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize; + if(!FLAC__seekable_stream_decoder_get_decode_position(decoder, &upper_bound)) { + decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; + return false; } } - if(pos < (FLAC__int64)lower_bound) - pos = (FLAC__int64)lower_bound; - last_frame_sample = this_frame_sample; } + else { + /* target_sample >= this_frame_sample + this frame's blocksize */ + + if(target_sample < this_frame_sample + 4 * decoder->private_->last_frame.header.blocksize) + needs_seek = false; + + lower_bound_sample = this_frame_sample + decoder->private_->last_frame.header.blocksize; + if(!FLAC__seekable_stream_decoder_get_decode_position(decoder, &lower_bound)) { + decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; + return false; + } + if(last_pos == (FLAC__int64)lower_bound) { + decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR; + return false; + } + last_pos = lower_bound; + } + last_frame_sample = this_frame_sample; } return true;
_______________________________________________ Flac-dev mailing list Flac-dev@xiph.org http://lists.xiph.org/mailman/listinfo/flac-dev