Ok, here is a patch waiting for new CVS :). It works fine for me, but
please check it before commiting...
--
Miroslav Lichvar
-------------- next part --------------
--- src/libFLAC/bitbuffer.c.orig 2003-01-30 17:36:01.000000000 +0100
+++ src/libFLAC/bitbuffer.c 2003-01-30 21:53:18.000000000 +0100
@@ -51,6 +51,25 @@
*/
static const unsigned FLAC__BITBUFFER_DEFAULT_CAPACITY = ((65536 - 64) * 8) /
FLAC__BITS_PER_BLURB; /* blurbs */
+static const unsigned char byte_to_unary_table[] = {
+ 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
#if FLAC__BITS_PER_BLURB == 8
#define FLAC__BITS_PER_BLURB_LOG2 3
#define FLAC__BYTES_PER_BLURB 1
@@ -58,6 +77,7 @@
#define FLAC__BLURB_TOP_BIT_ONE ((FLAC__byte)0x80)
#define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)'\x80') >> (b))
#define CRC16_UPDATE_BLURB(bb, blurb, crc) FLAC__CRC16_UPDATE((blurb), (crc));
+#define FLAC__ALIGNED_BLURB_UNARY(blurb) (byte_to_unary_table[blurb])
#elif FLAC__BITS_PER_BLURB == 32
#define FLAC__BITS_PER_BLURB_LOG2 5
#define FLAC__BYTES_PER_BLURB 4
@@ -65,6 +85,7 @@
#define FLAC__BLURB_TOP_BIT_ONE ((FLAC__uint32)0x80000000)
#define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)0x80000000) >> (b))
#define CRC16_UPDATE_BLURB(bb, blurb, crc) crc16_update_blurb((bb), (blurb));
+#define FLAC__ALIGNED_BLURB_UNARY(blurb) ((blurb) <= 0xff ?
byte_to_unary_table[blurb] + 24 : ((blurb) <= 0xffff ?
byte_to_unary_table[(blurb) >> 8] + 16 : ((blurb) <= 0xffffff ?
byte_to_unary_table[(blurb) >> 16] + 8 : byte_to_unary_table[(blurb)
>> 24])))
#else
/* ERROR, only sizes of 8 and 32 are supported */
#endif
@@ -2090,114 +2111,16 @@
if(nvals == 0)
return true;
+ cbits = bb->consumed_bits;
i = bb->consumed_blurbs;
- /*
- * We unroll the main loop to take care of partially consumed blurbs here.
- */
- if(bb->consumed_bits > 0) {
- save_blurb = blurb = buffer[i];
- cbits = bb->consumed_bits;
- blurb <<= cbits;
-
- while(1) {
- if(state == 0) {
- if(blurb) {
- for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++)
- blurb <<= 1;
- msbs += j;
-
- /* dispose of the unary end bit */
- blurb <<= 1;
- j++;
- cbits += j;
-
- uval = 0;
- lsbs_left = parameter;
- state++;
- if(cbits == FLAC__BITS_PER_BLURB) {
- cbits = 0;
- CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
- break;
- }
- }
- else {
- msbs += FLAC__BITS_PER_BLURB - cbits;
- cbits = 0;
- CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
- break;
- }
- }
- else {
- const unsigned available_bits = FLAC__BITS_PER_BLURB - cbits;
- if(lsbs_left >= available_bits) {
- uval <<= available_bits;
- uval |= (blurb >> cbits);
- cbits = 0;
- CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
-
- if(lsbs_left == available_bits) {
- /* compose the value */
- uval |= (msbs << parameter);
- if(uval & 1)
- vals[val_i++] = -((int)(uval >> 1)) - 1;
- else
- vals[val_i++] = (int)(uval >> 1);
- if(val_i == nvals)
- break;
-
- msbs = 0;
- state = 0;
- }
-
- lsbs_left -= available_bits;
- break;
- }
- else {
- uval <<= lsbs_left;
- uval |= (blurb >> (FLAC__BITS_PER_BLURB - lsbs_left));
- blurb <<= lsbs_left;
- cbits += lsbs_left;
-
- /* compose the value */
- uval |= (msbs << parameter);
- if(uval & 1)
- vals[val_i++] = -((int)(uval >> 1)) - 1;
- else
- vals[val_i++] = (int)(uval >> 1);
- if(val_i == nvals) {
- /* back up one if we exited the for loop because we read all nvals but
the end came in the middle of a blurb */
- i--;
- break;
- }
-
- msbs = 0;
- state = 0;
- }
- }
- }
- i++;
-
- bb->consumed_blurbs = i;
- bb->consumed_bits = cbits;
- bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits;
- }
-
- /*
- * Now that we are blurb-aligned the logic is slightly simpler
- */
while(val_i < nvals) {
- for( ; i < bb->blurbs && val_i < nvals; i++) {
- save_blurb = blurb = buffer[i];
- cbits = 0;
+ for( ; i < bb->blurbs; i++) {
+ blurb = (save_blurb = buffer[i]) << cbits;
while(1) {
if(state == 0) {
if(blurb) {
- for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++)
- blurb <<= 1;
+ j = FLAC__ALIGNED_BLURB_UNARY(blurb);
msbs += j;
-
- /* dispose of the unary end bit */
- blurb <<= 1;
j++;
cbits += j;
@@ -2209,6 +2132,7 @@
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
break;
}
+ blurb <<= j;
}
else {
msbs += FLAC__BITS_PER_BLURB - cbits;
@@ -2228,12 +2152,11 @@
if(lsbs_left == available_bits) {
/* compose the value */
uval |= (msbs << parameter);
- if(uval & 1)
- vals[val_i++] = -((int)(uval >> 1)) - 1;
- else
- vals[val_i++] = (int)(uval >> 1);
- if(val_i == nvals)
- break;
+ vals[val_i++] = (int)(uval >> 1 ^ (FLAC__int32)uval << 31
>> 31);
+ if(val_i == nvals) {
+ i++;
+ goto break2;
+ }
msbs = 0;
state = 0;
@@ -2250,15 +2173,9 @@
/* compose the value */
uval |= (msbs << parameter);
- if(uval & 1)
- vals[val_i++] = -((int)(uval >> 1)) - 1;
- else
- vals[val_i++] = (int)(uval >> 1);
- if(val_i == nvals) {
- /* back up one if we exited the for loop because we read all nvals but
the end came in the middle of a blurb */
- i--;
- break;
- }
+ vals[val_i++] = (int)(uval >> 1 ^ (FLAC__int32)uval << 31
>> 31);
+ if(val_i == nvals)
+ goto break2;
msbs = 0;
state = 0;
@@ -2266,6 +2183,7 @@
}
}
}
+break2:
bb->consumed_blurbs = i;
bb->consumed_bits = cbits;
bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits;
On Thu, Jan 30, 2003 at 10:35:29PM +0100, Miroslav Lichvar wrote:> Ok, here is a patch waiting for new CVS :). It works fine for me, but > please check it before commiting...Here is slightly better version of the patch. -- Miroslav Lichvar -------------- next part -------------- Index: src/libFLAC/bitbuffer.c ==================================================================RCS file: /cvsroot/flac/flac/src/libFLAC/bitbuffer.c,v retrieving revision 1.51 diff -u -r1.51 bitbuffer.c --- src/libFLAC/bitbuffer.c 31 Jan 2003 23:34:57 -0000 1.51 +++ src/libFLAC/bitbuffer.c 6 Feb 2003 17:08:42 -0000 @@ -63,6 +63,25 @@ */ static const unsigned FLAC__BITBUFFER_DEFAULT_CAPACITY = ((65536 - 64) * 8) / FLAC__BITS_PER_BLURB; /* blurbs */ +static const unsigned char byte_to_unary_table[] = { + 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, + 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + #if FLAC__BITS_PER_BLURB == 8 #define FLAC__BITS_PER_BLURB_LOG2 3 #define FLAC__BYTES_PER_BLURB 1 @@ -70,6 +89,7 @@ #define FLAC__BLURB_TOP_BIT_ONE ((FLAC__byte)0x80) #define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)'\x80') >> (b)) #define CRC16_UPDATE_BLURB(bb, blurb, crc) FLAC__CRC16_UPDATE((blurb), (crc)); +#define FLAC__ALIGNED_BLURB_UNARY(blurb) (byte_to_unary_table[blurb]) #elif FLAC__BITS_PER_BLURB == 32 #define FLAC__BITS_PER_BLURB_LOG2 5 #define FLAC__BYTES_PER_BLURB 4 @@ -77,6 +97,7 @@ #define FLAC__BLURB_TOP_BIT_ONE ((FLAC__uint32)0x80000000) #define BLURB_BIT_TO_MASK(b) (((FLAC__blurb)0x80000000) >> (b)) #define CRC16_UPDATE_BLURB(bb, blurb, crc) crc16_update_blurb((bb), (blurb)); +#define FLAC__ALIGNED_BLURB_UNARY(blurb) ((blurb) <= 0xff ? byte_to_unary_table[blurb] + 24 : ((blurb) <= 0xffff ? byte_to_unary_table[(blurb) >> 8] + 16 : ((blurb) <= 0xffffff ? byte_to_unary_table[(blurb) >> 16] + 8 : byte_to_unary_table[(blurb) >> 24]))) #else /* ERROR, only sizes of 8 and 32 are supported */ #endif @@ -2102,114 +2123,16 @@ if(nvals == 0) return true; + cbits = bb->consumed_bits; i = bb->consumed_blurbs; - /* - * We unroll the main loop to take care of partially consumed blurbs here. - */ - if(bb->consumed_bits > 0) { - save_blurb = blurb = buffer[i]; - cbits = bb->consumed_bits; - blurb <<= cbits; - - while(1) { - if(state == 0) { - if(blurb) { - for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++) - blurb <<= 1; - msbs += j; - - /* dispose of the unary end bit */ - blurb <<= 1; - j++; - cbits += j; - - uval = 0; - lsbs_left = parameter; - state++; - if(cbits == FLAC__BITS_PER_BLURB) { - cbits = 0; - CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16); - break; - } - } - else { - msbs += FLAC__BITS_PER_BLURB - cbits; - cbits = 0; - CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16); - break; - } - } - else { - const unsigned available_bits = FLAC__BITS_PER_BLURB - cbits; - if(lsbs_left >= available_bits) { - uval <<= available_bits; - uval |= (blurb >> cbits); - cbits = 0; - CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16); - - if(lsbs_left == available_bits) { - /* compose the value */ - uval |= (msbs << parameter); - if(uval & 1) - vals[val_i++] = -((int)(uval >> 1)) - 1; - else - vals[val_i++] = (int)(uval >> 1); - if(val_i == nvals) - break; - - msbs = 0; - state = 0; - } - - lsbs_left -= available_bits; - break; - } - else { - uval <<= lsbs_left; - uval |= (blurb >> (FLAC__BITS_PER_BLURB - lsbs_left)); - blurb <<= lsbs_left; - cbits += lsbs_left; - - /* compose the value */ - uval |= (msbs << parameter); - if(uval & 1) - vals[val_i++] = -((int)(uval >> 1)) - 1; - else - vals[val_i++] = (int)(uval >> 1); - if(val_i == nvals) { - /* back up one if we exited the for loop because we read all nvals but the end came in the middle of a blurb */ - i--; - break; - } - - msbs = 0; - state = 0; - } - } - } - i++; - - bb->consumed_blurbs = i; - bb->consumed_bits = cbits; - bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits; - } - - /* - * Now that we are blurb-aligned the logic is slightly simpler - */ while(val_i < nvals) { - for( ; i < bb->blurbs && val_i < nvals; i++) { - save_blurb = blurb = buffer[i]; - cbits = 0; + for( ; i < bb->blurbs; i++) { + blurb = (save_blurb = buffer[i]) << cbits; while(1) { if(state == 0) { if(blurb) { - for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++) - blurb <<= 1; + j = FLAC__ALIGNED_BLURB_UNARY(blurb); msbs += j; - - /* dispose of the unary end bit */ - blurb <<= 1; j++; cbits += j; @@ -2221,6 +2144,7 @@ CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16); break; } + blurb <<= j; } else { msbs += FLAC__BITS_PER_BLURB - cbits; @@ -2240,12 +2164,11 @@ if(lsbs_left == available_bits) { /* compose the value */ uval |= (msbs << parameter); - if(uval & 1) - vals[val_i++] = -((int)(uval >> 1)) - 1; - else - vals[val_i++] = (int)(uval >> 1); - if(val_i == nvals) - break; + vals[val_i++] = (int)(uval >> 1 ^ -(int)(uval & 1)); + if(val_i == nvals) { + i++; + goto break2; + } msbs = 0; state = 0; @@ -2255,22 +2178,16 @@ break; } else { + cbits += lsbs_left; uval <<= lsbs_left; uval |= (blurb >> (FLAC__BITS_PER_BLURB - lsbs_left)); blurb <<= lsbs_left; - cbits += lsbs_left; /* compose the value */ uval |= (msbs << parameter); - if(uval & 1) - vals[val_i++] = -((int)(uval >> 1)) - 1; - else - vals[val_i++] = (int)(uval >> 1); - if(val_i == nvals) { - /* back up one if we exited the for loop because we read all nvals but the end came in the middle of a blurb */ - i--; - break; - } + vals[val_i++] = (int)(uval >> 1 ^ -(int)(uval & 1)); + if(val_i == nvals) + goto break2; msbs = 0; state = 0; @@ -2278,6 +2195,7 @@ } } } +break2: bb->consumed_blurbs = i; bb->consumed_bits = cbits; bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits;
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 -------------- next part -------------- --- 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;
--- Miroslav Lichvar <lichvarm@phoenix.inf.upol.cz> wrote:> 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.yes, I still have it. I actually did apply it at one point but did not check it in because I had not tested it thoroughly. there have been so many seeking bugs and people get really upset when seeking doesn't work right, so I take extra care with changes. Josh __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
--- Miroslav Lichvar <lichvarm@phoenix.inf.upol.cz> wrote:> 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.yes, I still have it. I actually did apply it at one point but did not check it in because I had not tested it thoroughly. there have been so many seeking bugs and people get really upset when seeking doesn't work right, so I take extra care with changes. Josh __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com