[Kdenlive-devel] custom ffmpeg parameters question

[Harry van der Wolf]

Hi Jan,

This mail contains a lot of assumptions, I'm not sure here.
I start with something more about the audio options for DVD streams.
The standards are:

    * PCM: 48 kHz or 96 kHz sampling rate, 16 bit or 24 bit L-PCM, 2 to
      6 channels, up to 6144 kbit/s <http://en.wikipedia.org/wiki/Kbit/s>
    * AC-3: 48 kHz sampling rate, 1 to 5.1 (6) channels, up to 448 kbit/s
    * DTS: 48 kHz or 96 kHz sampling rate, 2 to 6.1 channels, Half Rate
      (768 kbit/s) or Full Rate (1536 kbit/s)
    * MP2: 48 kHz sampling rate, 1 to 7.1 channels, up to 912 kbit/s

Most encoders I have worked with, both on linux and windows, use for AC3 
encoding a bitrate of 384 or (almost the default) 448 kbit/s and for mp2 
(mpeg) mostly 192 kbit/s.
I saw from the exports.profile file (in 
/usr/share/apps/kdenlive/profiles) that kdenlive uses AC3 encoding with 
"only" 192 kbit/s (which makes my answer not correct in my previous mail).
You could try some custom option for export/render in kdenlive, or 
modify the line in the exports.profile
:HQ:DVD:PAL:::avformat:PAL:vob:format=dvd aspect=4:3 vcodec=mpeg2video 
acodec=ac3 video_bit_rate=6500000 video_rc_max_rate=8000000 
video_rc_min_rate=0 video_rc_buffer_size=1835008 mux_packet_size=2048 
mux_rate=10080000 audio_bit_rate=192000 audio_sample_rate=48000 
frame_size=720x576 frame_rate=25 gop_size=15 me_range=63

You could change the acodec=ac3 into acodec=mp3, leaving the 
audio_bit_rate=192000 as it is
or
leave the acodec=ac3 and change the audio bitrate to audio_bit_rate=448000

A friend of mine, but also I myself once had dvd-players which had 
difficulties playing DVD's with other settings that the defaults, even 
though the DVD-standard itself allows them. Obviously the build-in 
decoding used to much processing power on these non-standard streams. 
Please try the default settings for Kdenlive.

Kind regards,
Harry



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