Hi Carl

On 06/27/20 06:11, Carl Eugen Hoyos wrote:
Am Fr., 26. Juni 2020 um 21:56 Uhr schrieb Ruler2112 <ruler2...@charter.net>:

Step 3: Standardize Volume
Not performed by ffmpeg
I am curious: Why?


AFAIK, ffmpeg does not have the ability to analyze the volume of every sample throughout an audio file, find the greatest amplitude, calculate the adjustment needed to make the loudest part of the file the maximum, and then apply that scaled volume adjustment to the entire file. (While this doesn't equalize the volume or eliminate all volume-related inconsistencies, it does make the loudest part of each video the same and is the best solution I've found; I don't have to re-adjust my volume when playing ~95% of the files run through this script.) I've never seen anything about this in the documentation & frankly, it seems like it's something esoteric enough to be out of scope for the project. Am I wrong in this regard?

The two lines that are concerning to me are:

      'Guessed Channel Layout for Input Stream #1.0 : stereo'

Of course it's stereo - I jump dumped it to a 2-channel wave in the step 2!
  I'm guessing that I can safely ignore this one
(The wav standard does not require writing the channel layout for some
mono and stereo files and we don't do it to maintain compatibility with
ancient software that fails if the information is present.)

Interesting that this warning is not present in the windows version of ffmpeg yet is on Linux. Any idea why that would be? Even more interesting is your explanation... out of curiosity, what ancient software are you referring to? (Not really important - just curious.)

'Timestamps are unset in a packet for stream 0. This is deprecated and
will stop working in the future. Fix your code to set the timestamps
This warning is not meant for you and you cannot fix it.

Huh??? If it's not intended for the user and there's no way for the user to fix it, I assume it must be a warning specifically for developers. As such, why would it be printed without having some flag turned on to print debug warnings??? Never saw it when using the older windows version I was running and have found a LOT of people with the same question in my searching for a solution to this same message - this is the first time I've read this.

An idea just popped into my head... if someone involved with organizing the ffmpeg project reads this, you might want to start an 'error code' database where people could copy/paste the error they received and it would provide them information like this. It would certainly lighten the volume of repeated questions/problems to the mailing list and other forums. I pride myself on finding & fixing problems myself and only ask for help when I see no other choice; I'm glad I gave up on this when I did! A search of the mailing list archives for "timestamps are unset in a packet" came back with over 70 hits, and that doesn't include hits from all the other different forums I found. (Hopefully, each of those people didn't waste as much time as I did chasing a problem they had no hope of fixing.) I'm sure other errors are even more commonly repeated; a database of error messages could help reduce such repetition. Just an idea.

For future questions: Please understand that posting excerpts of the
console output is not acceptable, always post the command line(s)
together with the complete, uncut console output.

The output of the commands was complete except for version & library information, which were identical for every command. Please accept my apologies for not repeating the same information every time - I was just trying to shorten an already lengthy message by putting the version information once and eliminating redundant information throughout the rest of the message.

Thank you so much for your response Carl. The information you provided means that my script to reprocess video files on Linux is complete! (Assuming I don't run into anything weird when processing different video formats in the future of course. ;) ) I'm happy, happy, happy about that! :) :) :)


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