Displaying 9 results from an estimated 9 matches for "min_qlp_coeff_precision".
2015 Apr 18
2
"keep qlp coeff precision such that only 32-bit math is required"
stream_encoder.c has the following code:
/* try to keep qlp coeff precision such that only 32-bit math is required for decode of <=16bps streams */
if(subframe_bps <= 16) {
...
But FLAC can convert 16-bit input to 17-bit if mid-side coding is used.
So, does it make sense to compare subframe_bps with 17?
(The patch is attached. What do you think about it?)
-------------- next part
2014 Jul 28
1
Duplicate QLP coefficient restricting code
...ch of flac. This
switch should enable exhaustive search for the optimal qlp
coefficient precision, but the resulting files are usually 0.5%
larger then when not using the switch. I stumbled upon this code
in stream_encoder
> if(encoder->protected_->do_qlp_coeff_prec_search) {
> min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
> /* try to ensure a 32-bit datapath throughout for
> 16bps(+1bps for side channel) or less */
> if(subframe_bps <= 17) {
> max_qlp_coeff_precision = flac_min(32 - subframe_bps -
> lpc_order, FLAC__MAX_QLP_COEFF_PRECISION);
>...
2014 Jul 28
0
[PATCH] Fix bug when using -p switch during compression
...src/libFLAC/stream_encoder.c b/src/libFLAC/stream_encoder.c
index 9dfb0c5..8d4cfcc 100644
--- a/src/libFLAC/stream_encoder.c
+++ b/src/libFLAC/stream_encoder.c
@@ -3428,9 +3428,9 @@ FLAC__bool process_subframe_(
}
if(encoder->protected_->do_qlp_coeff_prec_search) {
min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
- /* try to ensure a 32-bit datapath throughout for 16bps(+1bps for side channel) or less */
- if(subframe_bps <= 17) {
- max_qlp_coeff_precision = flac_min(32 - subframe_bps - lpc_order, FLAC__MAX_QLP_COEFF_PRECISION);
+ /* try t...
2015 Apr 20
2
"keep qlp coeff precision such that only 32-bit math is required"
Martijn van Beurden wrote:
> Or maybe the question is: why is this code in evaluate_lpc_subframe anyway,
> i.e, why is this code duplicated? If process_subframe_ sets the
> qlp_precision for evaluate_lpc_subframe, why should the latter ignore that?
>
> We can only speculate about this, but I think this code has been duplicated
> by accident, and therefore it wasn't changed
2015 Apr 18
2
"keep qlp coeff precision such that only 32-bit math is required"
...hing, so look at the change log to see why the change came about.
Brian Willoughby
Sound Consulting
On Apr 18, 2015, at 12:20 PM, Brian Willoughby <brianw at audiobanshee.com> wrote:
> Hmm, I don't know the history of the code, but flac 1.2.1 stream_encoder.c has
>
> min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
> /* try to ensure a 32-bit datapath throughout for 16bps(+1bps for side channel) or less */
> if(subframe_bps <= 17) {
> max_qlp_coeff_precision = min(32 - subframe_bps - lpc_order, FLAC__MAX_QLP_COEFF_PRECISION);
>...
2012 Apr 05
2
[PATCH 2/2] V2: Use a single definition of MIN and MAX in sources
...ncoderInitStatus init_stream_internal_(
if(encoder->protected_->bits_per_sample < 16) {
/* @@@ need some data about how to set this here w.r.t. blocksize and sample rate */
/* @@@ until then we'll make a guess */
- encoder->protected_->qlp_coeff_precision = max(FLAC__MIN_QLP_COEFF_PRECISION, 2 + encoder->protected_->bits_per_sample / 2);
+ encoder->protected_->qlp_coeff_precision = flac_max(FLAC__MIN_QLP_COEFF_PRECISION, 2 + encoder->protected_->bits_per_sample / 2);
}
else if(encoder->protected_->bits_per_sample == 16) {
if(encoder->protected_-&...
2015 Apr 22
2
"keep qlp coeff precision such that only 32-bit math is required"
...ween MIN and MAX. So, if the
> qlp_coeff_precision value is limited in the loop but MAX is not
> limited, the loop does the exact same thing multiple times: a
> waste of time. Therefore, only the MAX should be limited.
>
> I don't think the logic is needed directly after
>> min_qlp_coeff_precision = max_qlp_coeff_precision = encoder->protected_->qlp_coeff_precision;
> because that value is either chosen by the encoder (it is a
> lookup value, and is always small enough not to trigger this,
> set in stream_encoder.c around line 700) or it is set through
> the encoder, in whi...
2007 Apr 08
0
FLAC 24 bit test results
...meter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER - 1);
#endif
rice_parameter = FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER - 1;
+ do_escape_coding = true;
}
if(encoder->protected_->do_qlp_coeff_prec_search) {
min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
@@ -3338,7 +3340,7 @@
rice_parameter,
min_partition_order,
max_partition_order,
- encoder->protected_->do_escape_coding,
+ do_escape_coding,
encoder->protected_->rice_parameter_search_di...
2007 Apr 05
2
FLAC 24 bit test results
On Thu, 2007-04-05 at 02:27 -0700, Brian Willoughby wrote:
> Josh (Green),
>
> Seems like the longest example in your list is a 15-second file. I
> would like to see the same problem exhibited in a file that is of a
> normal length. I have been recording full performances lasting
> hours, and flac always compresses the files below 70% of the original
> size.
>