[opus] 1.1 Much slower on Raspberry Pi
Stuart Marsden
stuartmarsden at finmars.co.uk
Tue Dec 17 02:48:49 PST 2013
Christian,
I will give 64kbit/s a try and post the figures. My own project is voice
only and requires low bitrate so was hoping that it was just the way I was
compiling and not an actual regression in speed for SILK. The raspberry PI
is quite a cheap and handy reference platform though the ARM side is fairly
underpowered but has a great GPU. It also has no audio in which is a pain
for playing with codecs but it does support USB soundcards. I was wondering
if a microcontroller like the Cortex-M range might be able to encode and
that seemed possible extrapolating from the Pi results but this speed
regression if it is real would kill that hope.
I should also probably try and compile the same version from the Raspbian
repos myself and if I also see a big slowdown then it is something wrong
with the way I am compiling. I am not a deb expert but it seemed like the
only optimisation they were using was -O2 but perhaps there is something
else set. Do not want to claim a regression when it may be my own fault.
Thanks for your response.
Best Regards,
Stuart Marsden
On 17 December 2013 11:04, Christian Hoene <christian.hoene at symonics.com>wrote:
> Hi Stuart,
>
>
>
> you are compressing it at 6kbit/s. Then, then SILK mode is probability
> used and the Silk mode is much faster than CELT. Do you also some figures
> at 64kbit/s?
>
>
>
> It is strange that Opus 1.1 got slower in the Silk mode – may the
> speech/voice selection adds some overhead. I would be interested in seeing
> the performance of the 64 kbit/s in both Opus 1.0 and Opus 1.1.
>
>
>
> With best regards,
>
>
>
> Christian Hoene
>
>
>
> PS:
> I also though on using Raspberry PI as a reference platform for testing
> the speech of Opus on a ARM processor. For measuring the speech
> of Opus on Intel CPUs, the MARSS86.org simulator might be appropriate.
>
>
>
>
>
>
>
>
>
>
>
> *Von:* opus-bounces at xiph.org [mailto:opus-bounces at xiph.org] *Im Auftrag
> von *Stuart Marsden
> *Gesendet:* Montag, 16. Dezember 2013 14:03
> *An:* opus at xiph.org
> *Betreff:* [opus] 1.1 Much slower on Raspberry Pi
>
>
>
> I have just started trying Opus with a view to using it in a project. I am
> interested in embedded hardware and tried it on the Raspberry Pi using the
> raspbian distro.
>
>
>
> The version of libopus in the repos is 0.9.14. I installed this and tried
> encoding 2 minutes of speech from a librevox recording. It managed this at
> a respectable pace for complexity 10:
>
>
>
> Skipping chunk of type "LIST", length 76
>
> Encoding using libopus 0.9.14 (audio)
>
> -----------------------------------------------------
>
> Input: 44.1kHz 1 channel
>
> Output: 1 channel (1 uncoupled)
>
> 20ms packets, 6kbit/sec VBR
>
> Preskip: 356
>
>
>
> Encoding complete
>
> -----------------------------------------------------
>
> Encoded: 2 minutes and 0.02 seconds
>
> Runtime: 50.9 seconds
>
> (2.358x realtime)
>
> Wrote: 111194 bytes, 6001 packets, 123 pages
>
> Bitrate: 6.78414kbit/s (without overhead)
>
> Rate range: 2.8kbit/s to 12kbit/s
>
> (7 to 30 bytes per packet)
>
> Overhead: 8.47% (container+metadata)
>
>
>
> And even faster on complexity 0:
>
>
>
> Skipping chunk of type "LIST", length 76
>
> Encoding using libopus 0.9.14 (audio)
>
> -----------------------------------------------------
>
> Input: 44.1kHz 1 channel
>
> Output: 1 channel (1 uncoupled)
>
> 20ms packets, 6kbit/sec VBR
>
> Preskip: 316
>
>
>
> Encoding complete
>
> -----------------------------------------------------
>
> Encoded: 2 minutes and 0.02 seconds
>
> Runtime: 23.72 seconds
>
> (5.059x realtime)
>
> Wrote: 106598 bytes, 6001 packets, 123 pages
>
> Bitrate: 6.47779kbit/s (without overhead)
>
> Rate range: 2.4kbit/s to 13.6kbit/s
>
> (6 to 34 bytes per packet)
>
> Overhead: 8.83% (container+metadata)
>
>
>
> I saw the 1.1 release notes and it said speed improvements on ARM so
> thought I would try. I downloaded from opus-codec.org and compiled
> directly on the Pi. It has however turned out a lot slower. Complexity 10
> barely can encode in realtime:
>
>
>
> Skipping chunk of type "LIST", length 76
>
> Encoding using libopus 1.1 (audio)
>
> -----------------------------------------------------
>
> Input: 44.1kHz 1 channel
>
> Output: 1 channel (1 uncoupled)
>
> 20ms packets, 6kbit/sec VBR
>
> Preskip: 356
>
>
>
> Encoding complete
>
>
> -----------------------------------------------------
>
> Encoded: 2 minutes and 0.02 seconds
>
> Runtime: 1 minute and 53 seconds
>
> (1.062x realtime)
>
> Wrote: 110743 bytes, 6001 packets, 123 pages
>
> Bitrate: 6.70782kbit/s (without overhead)
>
> Instant rates: 2.8kbit/s to 11.6kbit/s
>
> (7 to 29 bytes per packet)
>
> Overhead: 9.13% (container+metadata)
>
>
>
> And is also much slower at complexity 0:
>
>
>
> Skipping chunk of type "LIST", length 76
>
> Notice: Using resampling with complexity<10.
>
> Opusenc is fastest with 48, 24, 16, 12, or 8kHz input.
>
>
>
> Encoding using libopus 1.1 (audio)
>
> -----------------------------------------------------
>
> Input: 44.1kHz 1 channel
>
> Output: 1 channel (1 uncoupled)
>
> 20ms packets, 6kbit/sec VBR
>
> Preskip: 316
>
>
>
> Encoding complete
>
>
> -----------------------------------------------------
>
> Encoded: 2 minutes and 0.02 seconds
>
> Runtime: 36 seconds
>
> (3.334x realtime)
>
> Wrote: 106945 bytes, 6001 packets, 123 pages
>
> Bitrate: 6.45466kbit/s (without overhead)
>
> Instant rates: 2.4kbit/s to 12.8kbit/s
>
> (6 to 32 bytes per packet)
>
> Overhead: 9.45% (container+metadata)
>
>
>
> I tried compiling it as fixed point and it is slightly faster but no where
> near the older version. At complexity 10:
>
>
>
> Skipping chunk of type "LIST", length 76
>
> Encoding using libopus 1.1-fixed (audio)
>
> -----------------------------------------------------
>
> Input: 44.1kHz 1 channel
>
> Output: 1 channel (1 uncoupled)
>
> 20ms packets, 6kbit/sec VBR
>
> Preskip: 356
>
>
>
> Encoding complete
>
>
> -----------------------------------------------------
>
> Encoded: 2 minutes and 0.02 seconds
>
> Runtime: 1 minute and 42 seconds
>
> (1.177x realtime)
>
> Wrote: 110686 bytes, 6001 packets, 123 pages
>
> Bitrate: 6.70402kbit/s (without overhead)
>
> Instant rates: 2.4kbit/s to 11.2kbit/s
>
> (6 to 28 bytes per packet)
>
> Overhead: 9.13% (container+metadata)
>
>
>
>
>
> I have tried different compiler options but nothing has brought the speed
> back up.
>
>
>
> Any advice on the compiler flags or why I should be seeing such a big
> speed regression?
>
>
>
> Stuart Marsden
>
>
>
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