Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
On date Tuesday 2024-03-26 23:07:53 +, ffmpeg-devel Mailing List wrote: > Signed-off-by: Antoine Soulier > --- > configure | 6 ++ > 1 file changed, 6 insertions(+) still LGTM but should be merged with the encoder/decoder patch [...] ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
Compared with the C implementation of KissFFT (it's the only one I tested on ARM M4). Yes, there is no SIMD on x86. This was not the main target. Was mainly made for ARM M4 (for BLE devices Nordic Semi / Zephyr), and ARM Neon (Android). By the way, this does not change a lot, the FFT/MDCT on powerful CPU's is marginal compared to the read/write of the bitstream arithmetically coded. We can perhaps connect the FFMpeg implementation, but it will probably miss 2 things: - Some transformations are not a multiple of 15, but only 5 * 2^n. I guess FFmpeg only has a base 15 implementation. - It uses asymmetric windowing, to reduce algorithmic delay. Some coefficients are zeroed. Not important, but will need a larger coefficients table, and a bunch of multiplication by 0, without a specific implementation. So I think it will need some work. On Tue, Mar 26, 2024 at 10:45 AM Paul B Mahol wrote: > > > On Tue, Mar 26, 2024 at 6:07 PM Antoine Soulier > wrote: > >> What do you mean by sub-optimal? >> It's stacked by prime factors, and unrolled for FFT3 and FF5. >> The butterfly implementations of FFT3 and FF5, gives me slightly slower >> computation. FFT5 is done first, so it takes advantage of sin()/cos() >> values of 0 or 1. >> There are also no reordering steps (this stage is completely removed), >> but cannot run in-place. >> Benchmarks I made show that it runs slightly faster. >> > > Compared with what? > Where is at least x86 SIMD for that MDCT? > > >> >> On Tue, Mar 26, 2024 at 9:59 AM Paul B Mahol wrote: >> >>> >>> Isn't this using sub-optimal MDCT implementation? >>> >> ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
On Tue, Mar 26, 2024 at 6:07 PM Antoine Soulier wrote: > What do you mean by sub-optimal? > It's stacked by prime factors, and unrolled for FFT3 and FF5. > The butterfly implementations of FFT3 and FF5, gives me slightly slower > computation. FFT5 is done first, so it takes advantage of sin()/cos() > values of 0 or 1. > There are also no reordering steps (this stage is completely removed), but > cannot run in-place. > Benchmarks I made show that it runs slightly faster. > Compared with what? Where is at least x86 SIMD for that MDCT? > > On Tue, Mar 26, 2024 at 9:59 AM Paul B Mahol wrote: > >> >> Isn't this using sub-optimal MDCT implementation? >> > ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
Arf, sorry for that. I used `git send-email -s`, perhaps it's the source of the double signed-off. On Tue, Mar 26, 2024 at 10:32 AM Stefano Sabatini wrote: > On date Tuesday 2024-03-26 16:47:35 +, ffmpeg-devel Mailing List wrote: > > > Signed-off-by: Antoine Soulier > > Signed-off-by: Antoine SOULIER > > why the double sign-off? > > [...] > > LGTM. > ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
On date Tuesday 2024-03-26 16:47:35 +, ffmpeg-devel Mailing List wrote: > Signed-off-by: Antoine Soulier > Signed-off-by: Antoine SOULIER why the double sign-off? [...] LGTM. ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
What do you mean by sub-optimal? It's stacked by prime factors, and unrolled for FFT3 and FF5. The butterfly implementations of FFT3 and FF5, gives me slightly slower computation. FFT5 is done first, so it takes advantage of sin()/cos() values of 0 or 1. There are also no reordering steps (this stage is completely removed), but cannot run in-place. Benchmarks I made show that it runs slightly faster. On Tue, Mar 26, 2024 at 9:59 AM Paul B Mahol wrote: > > Isn't this using sub-optimal MDCT implementation? > ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-devel] [PATCH 1/5] configure: Add option for enabling LC3/LC3plus wrapper
Isn't this using sub-optimal MDCT implementation? ___ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
