[Speex-dev] Pre-roll calculation

Hermann Weber hermie.weber at gmx.de
Sun Jun 30 11:58:03 PDT 2013


In the documentation it is stated:

"Seeking in Opus requires decoding some pre-roll amount before playback 
to allow the internal state to converge (as if recovering from packet 

I have encoded a RAW mono 48 kHz, 16 bit file using

     m_enc = opus_encoder_create(48000, 1, 
     opus_encoder_ctl(m_enc, OPUS_SET_BITRATE(48000));
     opus_encoder_ctl(m_enc, OPUS_SET_VBR(0));

I would like to ask how I should calculate the pre-roll. I used 1920 
bytes, but that is too slow for my purpose (I can not afford decoding so 
much pre-roll).
What is the minimum?

Or can that not be defined?

Thank you!

H. Weber

More information about the Speex-dev mailing list