January 2024 - Cin - Cinelerra-GG Mailing Lists

LPCM in DVD - 44.1/32khz sample rate?
by Andrew Randrianasulu 21 Jan '24

21 Jan '24

According to this source (vlc) lpcm dvd audio supports lower frequencies like 44100/32000 hz - useful for direct dv transcoding for example .... https://github.com/videolan/vlc/blob/master/modules/codec/lpcm.c see lines 524, 608 Does this mean that libavcodec/pcm-dvdenc.c can be trivially extended to support those ? Same question for mplex. (it only supports 48/96 khz lpcm audio). I also found this table via mjpeg-users archives: https://dvd.sourceforge.net/dvdinfo/lpcm.html it lists dynamic range/gain (?) setting equations. Not mplex nor ffmpeg support setting this to anything but hardcoded 0x80 This might be source of my "too loud" lpcm dvd experiments because I was making lpcm file via cinelerra-gg's raw pcm output format (using libsndfile internally).

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Sox and mplex
by Andrew Randrianasulu 21 Jan '24

21 Jan '24

Canonical way to use mplex with lpcm sound seems to involve sox https://marc.info/?l=mjpeg-users&m=112004582102258&w=2 ==== 1. sox NAME.wav -t raw -x -s -w -c2 -r48000 NAME.lpcm 2. mplex -S 0 -f 8 -V -o NAME.mpg NAME.lpcm NAME.m2v === I also found at mjpeg-users list this utility that makes wavs into lpcm http://dvd-audio.sourceforge.net/wav2lpcm.tar.gz only 48/96 khz, 16/24bits stereo wavs are supported Also, this little table suggest there IS dynamic range bit in lpcm header https://dvd.sourceforge.net/dvdinfo/lpcm.html dynamic_range X 3 X High 3 bits of byte. dynamic_range Y 5 Y Lower 5 bits of byte linear gain = 2^(4-(X+(Y/30))) in dB gain = 24.082 - 6.0206 X - 0.2007 Y Also, according to this post 24-bit lpcm worked around mjpegtools-1.8.0 release: https://marc.info/?l=mjpeg-users&m=112912922124144&w=2 all this quite theoretical at this point, not tried it yet.

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video on LPCM DVD from DV method
by Andrew Randrianasulu 20 Jan '24

20 Jan '24

https://youtu.be/-NE2LZsVUjo grand total of two and half minutes at whooping 5 fps.

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attempt at fixing too loud sound with raw pcm output
by Andrew Randrianasulu 20 Jan '24

20 Jan '24

try andy dv test file, render only audio as Big Endian, Signed, 16 bits. Load it back and watch too loud audio. note: wav file not tested

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SD 16:9 missing among CinGG BD-Render Video Formats
by Terje J. Hanssen 19 Jan '24

19 Jan '24

According to wikipedia, 16:9 SD video formats are also valid BD-Video formats https://en.wikipedia.org/wiki/Blu-ray#Video SD 720 × 480 29.97i 4:3 or 16:9[d] (anamorhic) 720 × 576 25i 4:3 or 16:9[d] The Create BD Format contains 720 x 576/ 25i/p and 720 x 480/ 29.97i/p Please verify if this these are SD 4:3 only? The wikipedia table lists only SD interlaced as valid SD BD-Video format If so, SD 16:9 interlaced are missing, while SD progressive are invalid?

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small cleanup patch for filedv.h
by Andrew Randrianasulu 19 Jan '24

19 Jan '24

according to my grep-fu this define not used anywhere, probably remnant from some cinelerra-cv era experiments in using ffmpeg for dv (today we can do the same directly) grep DV_USE_FFMPEG cinelerra/* grep: cinelerra/data: Это каталог cinelerra/filedv.h:#ifdef DV_USE_FFMPEG grep: cinelerra/i686: Это каталог grep: cinelerra/tests: Это каталог

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mp2 audio profile
by Andrew Randrianasulu 19 Jan '24

19 Jan '24

put in ffmpeg/audio may be you can change codec (second mp2) to libtwolame, different ffmpegs offer different versions when I query for mp2 encoder A..... mp2 MP2 (MPEG audio layer 2) A..... mp2fixed MP2 fixed point (MPEG audio layer 2) (codec mp2) A..... libtwolame libtwolame MP2 (MPEG audio layer 2) (codec mp2) from desktop (v 4.4.4) A....D mp2 MP2 (MPEG audio layer 2) A....D mp2fixed MP2 fixed point (MPEG audio layer 2) (codec mp2) from termux (v 6.1)

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dvdisaster, a tool for creating error correction data for optical media
by Terje J. Hanssen 16 Jan '24

16 Jan '24

I just discovered this tool that aims to make backups on CD, DVD and BD discs safer. Any knowledge or experience with it? https://dvdisaster.jcea.es/ https://dvdisaster.jcea.es/misc.html#manual

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mpeg2 hdv profile based on MLT profile
by Andrew Randrianasulu 16 Jan '24

16 Jan '24

attached just put where all other cinelerra-gg's video profiles live ... note, this is for progressive 25f 1080p HDV if you have mlt installed you can inspect other files usually in /usr/share/mlt-7/presets/consumer/avformat/hdv_* those profiles does not seem to carry interlacing info but I hope we for now carry it correctly ....

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Anamorphic 16:9 SD Bluray
by Andrew Randrianasulu 16 Jan '24

16 Jan '24

so, it seems aspect_ratio not communicated currently correctly for this case but you can manually set aspect for ffmpeg video format to -> 1.77778/(720/576) = 1.42222 or SAR= DAR/PAR because ffmpeg really assumes we set SAR ! put aspect=1.42222 in additional codec options edit window. I'll think about how to automate it ....

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