search for: subframe_bps

I changed the condition in *_precompute_partition_info_sums_*() functions from if(bps <= 16) to if(FLAC__bitmath_ilog2(default_partition_samples) + bps < 32) and then changed the 'subframe_bps' argument of find_best_partition_order_() in evaluate_fixed_subframe_() and evaluate_lpc_subframe_() as follows: evaluate_fixed_subframe_(): evaluate_lpc_subframe_(): 1) subframe_bps + order subframe_bps + 0 2) subframe_bps + order subframe_bps + 2 3) subframe_bps +...

...4 is enough to fix this problem > > with FLAC__fixed_compute_residual(). > > > On the other hand, it is possible to set FLAC__MAX_EXTRA_RESIDUAL_BPS > to 0, and change evaluate_fixed_subframe_() function instead: in the call > of find_best_partition_order_() function, replace subframe_bps > with subframe_bps + order. Adding the extra bits to bps in evaluate_fixed_subframe_ instead of precompute_partition_info_sums_ is ok with me, that's what I suggested in the original thread discussing this problem, but I think it should be done also in the lpc function. Adding order instea...

lvqcl wrote: > I changed the condition in *_precompute_partition_info_sums_*() > functions from > if(bps <= 16) > to > if(FLAC__bitmath_ilog2(default_partition_samples) + bps < 32) > > and then changed the 'subframe_bps' argument of find_best_partition_order_() > in evaluate_fixed_subframe_() and evaluate_lpc_subframe_() as follows: > > evaluate_fixed_subframe_(): evaluate_lpc_subframe_(): > 1) subframe_bps + order subframe_bps + 0 > 2) subframe_bps + order subframe_b...

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 -------------- A non-text attachment was scrubbed... Name: bps.patch Type:...

libFLAC limits the value of qlp_coeff_precision to make sure that 32-bit math is enough for decoding of 16-bit audio. subframe_bps can be equal to 17 for 16-bit input (for side channel). So the value of subframe_bps should be compared with 17, not 16 (see also http://git.xiph.org/?p=flac.git;a=blob;f=src/libFLAC/stream_encoder.c;hb=02591f6b4b09e7c6e26bd2ae7225ff2810b227bb#l3431 ) -------------- next part -------------- A non-...

On Thu, Jun 19, 2014 at 06:25:57PM +0400, lvqcl wrote: > Now I wonder why evaluate_lpc_subframe_() function in stream_encoder.c contains > almost the same code, but without any comments that it's not enough pessimistic: > evaluate_lpc_subframe_(): > > if(subframe_bps + qlp_coeff_precision + FLAC__bitmath_ilog2(order) <= 32) > if(subframe_bps <= 16 && qlp_coeff_precision <= 16) > encoder->private_->local_lpc_compute_residual_from_qlp_coefficients_16bit(...); > else > encoder->private_->local_lpc_compute_residual_fro...

Erik de Castro Lopo wrote: >> It slightly improves the performance with standard encoding levels and >> 16-bit files as the 17-bit side channel can still be processed with the >> 32-bit accumulator and correctly selects the 64-bit accumulator with >> very large 16-bit partitions. >> >> This is related to commits 6f7ec60c and 187e596e. > > Sorry I

...witch. 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); > max_qlp_coeff_precision = > flac_max(max_qlp_coeff_precision, min_qlp_coeff_precision); > } > else > max_qlp_coeff_precision = F...

...+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 to keep qlp coeff precision such that only 32-bit math is required for decode of <=16bps streams */ + if(subframe_bps <= 16) { + max_qlp_c...

On Thu, Jun 19, 2014 at 03:30:22PM +0400, lvqcl wrote: > BTW, what can you say about the following place in stream_decoder.c > in read_subframe_lpc_() function: > > /*@@@@@@ technically not pessimistic enough, should be more like > if( (FLAC__uint64)order * ((((FLAC__uint64)1)<<bps)-1) * ((1<<subframe->qlp_coeff_precision)-1) < (((FLAC__uint64)-1)

...eam_encoder.c --- src/libFLAC/stream_encoder.c 18 Oct 2002 05:49:20 -0000 1.49 +++ src/libFLAC/stream_encoder.c 20 Oct 2002 11:37:18 -0000 @@ -2267,10 +2267,11 @@ if(ret != 0) return 0; /* this is a hack to indicate to the caller that we can't do lp at this order on this subframe */ - if(subframe_bps <= 16 && qlp_coeff_precision <= 16) - encoder->private_->local_lpc_compute_residual_from_qlp_coefficients_16bit(signal+order, residual_samples, qlp_coeff, order, quantization, residual); - else if(subframe_bps + qlp_coeff_precision + order <= 32) - encoder->private_->...

...m> 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); > max_qlp_coeff_precision = max(max_qlp_coeff_precision, min_qlp_coeff_precision); > } > > in process_subframe_(), whereas evaluate_lpc_subframe_()...

Miroslav Lichvar wrote: > On Wed, Jul 17, 2013 at 07:45:53PM +1000, Erik de Castro Lopo wrote: > > The fix was changing one local variable from FLAC_uint32 to FLAC_uint64 > > in function precompute_partition_info_sums_(). > > > > https://git.xiph.org/?p=flac.git;a=commit;h=6f7ec60c7e7f05f5ab0b1cf6b7b0945e44afcd4b > > I don't like this fix. It will

...AC__MAX_EXTRA_RESIDUAL_BPS == 4 is enough to fix this problem > with FLAC__fixed_compute_residual(). On the other hand, it is possible to set FLAC__MAX_EXTRA_RESIDUAL_BPS to 0, and change evaluate_fixed_subframe_() function instead: in the call of find_best_partition_order_() function, replace subframe_bps with subframe_bps + order. ...And maybe it's also better to use 'subframe_bps + order' instead of 'order' in calculation of 'estimate' variable in evaluate_fixed_subframe_()?

...artijn van Beurden wrote: > Yes, indeed. I removed the 17-bits part because I just matched > the code in evaluate_lpc_subframe_ with the process_subframe_ > code. It appears it only makes sense that those two pieces code > are the same. A bit of history: 1) The conditional "if(subframe_bps <= 16)" was added to evaluate_lpc_subframe_() in the commit http://git.xiph.org/?p=flac.git;a=commitdiff;h=20ac2c1cac298b8c0666e191ae913f6481e79879 2) The conditional "if(subframe_bps <= 16)" was added to process_subframe_() in the commit http://git.xiph.org/?p=flac.git;a=com...

Erik de Castro Lopo wrote: > There should be some indication of why in the git history. http://git.xiph.org/?p=flac.git;a=commitdiff;h=27846708fe6271e5e3965a4bbad99baa1ca24c49 Now I remember a discussion about a bug in -p switch: the old code substracts lpc_order instead of FLAC__bitmath_ilog2(lpc_order), and this commit fixes this. It seems that the logic in process_subframe_() and in

...when encoding: #0 0x200000e7304 in FLAC__fixed_compute_residual (data=0x1202b9c54, data_len=4607, order=1, residual=0x1202e6cc0) at fixed.c:165 #1 0x200000e1f44 in encoder_evaluate_fixed_subframe_ (signal=0x1202b9c50, residual=0x1202e6cc0, abs_residual=0x1202fd510, blocksize=4608, subframe_bps=8, order=1, rice_parameter=1, max_partition_order=4, subframe=0x200002aa2b0) at encoder.c:1028 #2 0x200000e1764 in encoder_process_subframe_ (encoder=0x1202b9bf0, max_partition_order=4, verbatim_only=0, frame_header=0x11ffff850, subframe_bps=8, integer_signal=0x1202b9c50, real_signa...

...partition_order, max_partition_order); /* * Setup the frame @@ -3332,8 +3323,8 @@ FLAC__bool process_subframe_( 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); - max_qlp_coeff_precision = max(max_qlp_coeff_precision, min_qlp_coeff_precision); + max_qlp_coeff_precision = flac_min(32 - subframe_bps - lpc_order, FLAC__MAX_QLP_...

...idual_partitioned_rice_ (bb=0x4085c800, residual=0x8361200, residual_samples=4580, predictor_order=28, rice_parameters=0x407dc520, raw_bits=0x407fc520, partition_order=0) at encoder_framing.c:366 #7 0x80563eb in FLAC__subframe_add_lpc (subframe=0x407dc518, residual_samples=4580, subframe_bps=17, wasted_bits=0, bb=0x4085c800) at encoder_framing.c:310 #8 0x80544c8 in encoder_add_subframe_ (encoder=0x8314758, frame_header=0xbfffe5ac, subframe_bps=17, subframe=0x407dc514, frame=0x4085c800) at encoder.c:1030 #9 0x8053b48 in encoder_process_subframes_ (encoder=0x8314758,...

Problems in FLAC 0.9: - On alpha, flac immediately dumps core for both encoding and decoding (FreeBSD/alpha). - The distribution Makefile.in files haven't been generated with "automake --include-deps". The resulting Makefiles aren't fully portable; in particular they break with BSD make. In the future, care should be taken to use "--include-deps". - What is