[Cin] Blu-ray encoding again

Andrew Randrianasulu randrianasulu at gmail.com
Thu Nov 14 18:14:04 CET 2019


В сообщении от Thursday 14 November 2019 19:59:16 Good Guy написал(а):
> the log messages for dev type are a bug, but it does not fail the render.
> The function: AVHWDeviceType FFVideoStream::decode_hw_activate()
> is using the translation for "none" to detect the intent not to use the hw.
>         if( hw_dev && *hw_dev && strcmp(_("none"), hw_dev) ) {
> Apparently your init is applying the english version, as it is in the log
> msg.
> The result of the hw probe is the same in both cases, and is not a fail.
> *I will change this to check both with and without get_text() so that it*
> *will not report if LANG is not applied.*

Oh, this is cosmetical issue (I hope), but thanks for caring about those messages ..and users!

> 
> "Warning: Do not use the option x264opts, as it will eventually be removed.
> Use x264-params instead."
> *ok.  we will change that.*
> 
> f*or bluray_format, mpegts_m2ts_mode=1 *(changed to 2 by me) causes the
> transport stream to set
> the transport_priority flag if the packet is audio ac3, which is sort of a
> kludge... but this is
> necessary to get audio to reproduce on my home bluray player (samsung
> ubd-k8500).  This was
> discovered by checking the diff between the ffmpeg output (which fails on
> player) and the "sintel"
> iso file from blender site (which works on player).  The mode=2 triggers
> mode=1 and add the
> transport_priority flag for ac3 audio.  It definitely helps here at home.
> Similarly, *sdt_period=-1*
> turns off the service descriptor table output, since this is not a
> broadcast stream.  I am not an
> expert on mpegts and these changes work for me.  If you have better
> information, let me know.

I'm not expert too, but may be Marton can explain to us 
if those changes acceptable in upstream, or they 
must be done as separate parameters ..


> 
> *for bluray.m2ts*, you have added
> fake-interlaced=1
> bitrate=40000
> slices=4
> sar=1:1
> # vbv-maxrate=40000
> # vbv-bufsize=30000
> cin_pix_fmt=yuv420p
> x264opts ... vbv-maxrate=40000:vbv-bufsize=30000
> 
> These are all good, except that bitrate is computed in bdcreate.C and set
> in the codec parameters
> for avcodec_open2 call (of open_encoder).  Recently we discovered that the
> "bitrate" param does
> not always work (change applied 20190922 git e620b69f).  If it is
> specified, it seems to override
> the codec params (at least in some cases) and the computed rate (that
> prevents the disc from
> overflowing) is lost.  If you are sure, I can add this, but I do not
> recommend it.

No, I think I just used "bitrate" trying to make encoder work. Just tried
without this parameter - it still works


> 
> Phyllis is going to try these changes, and if they work here at home, then
> they are good.

I think you can keep format/bluray with ffmpeg-4.2 (modified by your version of patch),
and only alter video/bluray.m2ts One thing at a time 
(also, if your player accept DVD-R you can save on BD disk...)


I think bdcreate.C can be modified around lines 330/331 to automagically add 
fake-interlaced=1 to options IF BD profile set to progressive ...

But conditionally replacing keyint=25 with another string..I don't know how to do this,
found this example on the net:

https://www.linuxquestions.org/questions/programming-9/replace-a-substring-with-another-string-in-c-170076/

#include <stdio.h>
#include <string.h>

char *replace_str(char *str, char *orig, char *rep)
{
  static char buffer[4096];
  char *p;

  if(!(p = strstr(str, orig)))  // Is 'orig' even in 'str'?
    return str;

  strncpy(buffer, str, p-str); // Copy characters from 'str' start to 'orig' st$
  buffer[p-str] = '\0';

  sprintf(buffer+(p-str), "%s%s", rep, p+strlen(orig));

  return buffer;
}

int main(void)
{
  puts(replace_str("Hello, world!", "world", "Miami"));

  return 0;
}

so, in our case str will be options string, orig will be keyint=25 (from opts file)
and rep will be some value derived from selected BD profile ... I think ...



> 
> Thanks for the good work.  Stay tuned.

I will!


> 
> gg
> 




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