Petr Pařízek
2025-Jan-24 17:03 UTC
[opus] Opus 1.5.2 low hum in input file results overblown output at decoding
There was a post in the Opus subthread on HA where there was a link to the file called Opus-tools-0.2-34-g98f3ddc_(using_libopus_1.5.2-21-gff6dea5)_Win_GCC142.7z. That's the one I'm currently using. First, I used GoldWave to convert your input file from ?-law to PCM and saved it as a ".wav" file. Next, I encoded it with Opusenc, I decoded its result with Opusdec with the target sample rate being set to 48 kHz, and I got no excessive amplification. Not sure what's taking place on your side. Petr
Kevin O'Connor
2025-Jan-28 18:53 UTC
[opus] Opus 1.5.2 low hum in input file results overblown output at decoding
Thanks for looking into this. I've played with the options I'm setting on the decoder and narrowed the issue down to DTX. If DTX is enabled, I get the reported behavior, but it does not happen with DTX disabled. I've posted a revised example: https://github.com/xiph/opus/issues/382 In this new version, I've removed the Microsoft-specific code and it runs/reproduces on Linux now as well. Also, to simplify things further, I replaced the mu-law input file with a linear16 sample file and removed the extra code to do the conversion from mu-law to linear in the sample app. I don't believe that the opustools utilities support controlling DTX option, so I don't think this can be reproduced using those tools. But if you have a built opus and a recent C++ compiler, it should be dead simple to compile and run this sample application. I put an example command line for compiling under Linux in the README. My application is mostly network transmitted audio (RTP) containing speech, so disabling DTX is very undesirable. Kevin O'Connor -----Original Message----- From: opus <opus-bounces at xiph.org> On Behalf Of Petr Par?zek Sent: Friday, January 24, 2025 12:03 PM To: opus at xiph.org Subject: Re: [opus] Opus 1.5.2 low hum in input file results overblown output at decoding ?EXTERNAL EMAIL - Please use caution with links and attachments? There was a post in the Opus subthread on HA where there was a link to the file called Opus-tools-0.2-34-g98f3ddc_(using_libopus_1.5.2-21-gff6dea5)_Win_GCC142.7z. That's the one I'm currently using. First, I used GoldWave to convert your input file from ?-law to PCM and saved it as a ".wav" file. Next, I encoded it with Opusenc, I decoded its result with Opusdec with the target sample rate being set to 48 kHz, and I got no excessive amplification. Not sure what's taking place on your side. Petr _______________________________________________ opus mailing list opus at xiph.org http://lists.xiph.org/mailman/listinfo/opus