Search for "surround" left/channel back. To me it looks the flac decoder is correct.
https://datatracker.ietf.org/doc/rfc9639/ On Wed, Jan 29, 2025 at 4:37 PM MrNice <wxcvbn2...@iol.ie> wrote: > > On 29/01/2025 11:26, Paul B Mahol wrote: > > For your specific case, one would need to look at flac specification, and > > check does ffmpeg follow specification correctly. > > > > On Wed, Jan 29, 2025 at 10:24 AM MrNice <wxcvbn2...@iol.ie> wrote: > > > >>>> On Jan 28, 2025, at 4:14 PM, MrNice <wxcvbn2...@iol.ie> wrote: > >>>> > >>>> On 28/01/2025 18:26, Carl Zwanzig wrote: > >>>>> On 1/28/2025 8:18 AM, MrNice wrote: > >>>>>> have an audio file, with MediaInfo I get > >>>>>> Audio > >>>>>> Channel layout : L R Ls Rs > >>>>>> > ffmpeg -v error -layouts | awk '/quad /{print $2}' > >>>>>> FL+FR+BL+BR > >>>>>> What is the correct answer? > >>>>> Both. > >>>>> Left, assumed to be front (L) = Front Left (FL) > >>>>> Left surround/side (Ls) = Back Left (BL) > >>>>> etc > >>>>> > >>>>> (that's part way down the AudioChannelManipulation page, even farther > >> down is a list of the channel names and standard layouts, also in the > >> -layouts output) > >>>>> z! > >>>>> > >>>>> _______________________________________________ > >>>> Are you sure for good Carl? > >>>> > >>>> AFAIK, LS is surround and BL is back/Rear > >>>> > >>>> Please look here > >>>> > >>>> https://mediaarea.net/AudioChannelLayout > >>>> > >>>> They say, depending of standardization; > >>>> Left Surround = Ls = CL = SL = Ls (MediaInfo name) > >>>> Right Surround = Rs = CR = SR = Rs (MediaInfo name) > >>>> Left Rear Surround = Lrs = BL = Lsr = SL = Lb (MediaInfo name) > >>>> Right Rear Surround = Rrs = BR = Rsr = Rb (MediaInfo name) > >>>> > >>> I'm not sure I understand the question, but I believe that "back" > >> channels are only involved if there are more than 5 distinct audio > signals > >> plus one low frequency signal. By way of explanation, I believe that 5 > >> distinct audio signals plus one low frequency signal is the > configuration > >> commonly referred to as "5.1" audio (front left, front right, center, > side > >> left, side right, and low frequency). I don't believe that the term > "5.1" > >> when used to describe an audio standard (summarized as the description > of > >> speaker locations listed in my previous sentence) specifies any "back' > >> audio signals at all. If you wish to convert 5.1 audio to an audio > format > >> having more distinct signals or sends, then I think it is up to you to > >> determine how you would like to distribute the audio signals to make > use of > >> the additional available channels. Did I say anything useful, or have I > >> just confused the issue? > >>> LL > >>> > >>> _______________________________________________ > >> Thank you for your answer. > >> > >> The point is that ffmpeg and MediaInfo do not output the same answer for > >> the channels positions. Side is not Back particularly in the last > >> century with quadrophonic. > >> > >> Or the information embedded in the file is confusing or one of the two > >> programs decipher the embedded info in a wrong way. It could be > >> interesting to know what is effectively coded inside the file and as > >> well how the 2 programs decipher and output that data to understand the > >> difference. > >> > >> Moreover, to get an accurate knowledge on ffmpeg, it could be > >> interesting to copy the table https://mediaarea.net/AudioChannelLayout > >> in the ffmpeg documentation and add one column with the corresponding > >> ffmpeg output. > >> > >> MrNice > >> > >> _______________________________________________ > >> ffmpeg-user mailing list > >> ffmpeg-user@ffmpeg.org > >> https://ffmpeg.org/mailman/listinfo/ffmpeg-user > >> > >> To unsubscribe, visit link above, or email > >> ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > >> > > _______________________________________________ > > Unfortunately, I am not skilled enough in that matter to go this way. > > Is there de developer who could complete the table > > https://mediaarea.net/AudioChannelLayout > > With the ffmpeg/ffprobe output ? > > > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
