Also note that still channel layouts in FFmpeg do not store/signal anywhere real channel horizontal/vertical angle.
On Wed, Jan 29, 2025 at 4:46 PM Paul B Mahol <one...@gmail.com> wrote: > 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".
