2.1 downmix with libfdk_aac using ffmpeg
I have several input media files I'd like to process. The input audio stream of each file is encoded in ac-3 with a 5.1 channel layout (back or side) at 384kbps.
The objective is for the target media file to contain a downmixed audio stream converted to 2.1 channel layout (at 192kbps) in aac format!
I use ffmpeg for the entire process and I can achieve the objective using the following parameters:
ffmpeg -i infile.mp4 -vn -c:a aac -b:a 192k -filter_complex "pan=2.1|FL<c0+c2+c4|FR<c1+c2+c5|LFE=c2" outfile.m4a
The resulting audio file has the following properties:
Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 2.1, fltp, 192 kb/s (default)
However(!) if I use libfdk_aac instead, I end up with a stereo file and the LFE channel being dropped:
Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16, 192 kb/s (default)
How do I encode the audio stream using libfdk_aac without dropping the LFE channel?
The result is the same when using automatic channel mapping. The following command produces a 2.1 audio stream when using aac instead of libfdk_aac as audio codec option:
ffmpeg -y -i infile.mp4 -vn -c:a aac -b:a 192k -af pan=2.1 test.m4a
For the sake of this questions I neglect all properties of the source video material as I am convinced it is not important to the answer of the question.
ffmpeg aac
asked Jan 8 at 4:40
der_michaelder_michael
2910
add a comment |
I have several input media files I'd like to process. The input audio stream of each file is encoded in ac-3 with a 5.1 channel layout (back or side) at 384kbps.
The objective is for the target media file to contain a downmixed audio stream converted to 2.1 channel layout (at 192kbps) in aac format!
I use ffmpeg for the entire process and I can achieve the objective using the following parameters:
ffmpeg -i infile.mp4 -vn -c:a aac -b:a 192k -filter_complex "pan=2.1|FL<c0+c2+c4|FR<c1+c2+c5|LFE=c2" outfile.m4a
The resulting audio file has the following properties:
Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 2.1, fltp, 192 kb/s (default)
However(!) if I use libfdk_aac instead, I end up with a stereo file and the LFE channel being dropped:
Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16, 192 kb/s (default)
How do I encode the audio stream using libfdk_aac without dropping the LFE channel?
The result is the same when using automatic channel mapping. The following command produces a 2.1 audio stream when using aac instead of libfdk_aac as audio codec option:
ffmpeg -y -i infile.mp4 -vn -c:a aac -b:a 192k -af pan=2.1 test.m4a
For the sake of this questions I neglect all properties of the source video material as I am convinced it is not important to the answer of the question.
ffmpeg aac
asked Jan 8 at 4:40
der_michaelder_michael
2910
In this post, I don't see 2.1 as listed format supported bylibfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC
– der_michael
Jan 8 at 4:41
add a comment |
I have several input media files I'd like to process. The input audio stream of each file is encoded in ac-3 with a 5.1 channel layout (back or side) at 384kbps.
The objective is for the target media file to contain a downmixed audio stream converted to 2.1 channel layout (at 192kbps) in aac format!
I use ffmpeg for the entire process and I can achieve the objective using the following parameters:
ffmpeg -i infile.mp4 -vn -c:a aac -b:a 192k -filter_complex "pan=2.1|FL<c0+c2+c4|FR<c1+c2+c5|LFE=c2" outfile.m4a
The resulting audio file has the following properties:
Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 2.1, fltp, 192 kb/s (default)
However(!) if I use libfdk_aac instead, I end up with a stereo file and the LFE channel being dropped:
Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16, 192 kb/s (default)
How do I encode the audio stream using libfdk_aac without dropping the LFE channel?
The result is the same when using automatic channel mapping. The following command produces a 2.1 audio stream when using aac instead of libfdk_aac as audio codec option:
ffmpeg -y -i infile.mp4 -vn -c:a aac -b:a 192k -af pan=2.1 test.m4a
For the sake of this questions I neglect all properties of the source video material as I am convinced it is not important to the answer of the question.
ffmpeg aac
asked Jan 8 at 4:40
der_michaelder_michael
2910
I have several input media files I'd like to process. The input audio stream of each file is encoded in ac-3 with a 5.1 channel layout (back or side) at 384kbps.
The objective is for the target media file to contain a downmixed audio stream converted to 2.1 channel layout (at 192kbps) in aac format!
I use ffmpeg for the entire process and I can achieve the objective using the following parameters:
ffmpeg -i infile.mp4 -vn -c:a aac -b:a 192k -filter_complex "pan=2.1|FL<c0+c2+c4|FR<c1+c2+c5|LFE=c2" outfile.m4a
The resulting audio file has the following properties:
Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 2.1, fltp, 192 kb/s (default)
However(!) if I use libfdk_aac instead, I end up with a stereo file and the LFE channel being dropped:
Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16, 192 kb/s (default)
How do I encode the audio stream using libfdk_aac without dropping the LFE channel?
The result is the same when using automatic channel mapping. The following command produces a 2.1 audio stream when using aac instead of libfdk_aac as audio codec option:
ffmpeg -y -i infile.mp4 -vn -c:a aac -b:a 192k -af pan=2.1 test.m4a
For the sake of this questions I neglect all properties of the source video material as I am convinced it is not important to the answer of the question.
ffmpeg aac
ffmpeg aac
asked Jan 8 at 4:40
der_michaelder_michael
2910
asked Jan 8 at 4:40
der_michaelder_michael
2910
asked Jan 8 at 4:40
der_michaelder_michael
2910
asked Jan 8 at 4:40
der_michaelder_michael
2910
asked Jan 8 at 4:40
der_michaelder_michael
2910
2910
In this post, I don't see 2.1 as listed format supported bylibfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC
– der_michael
Jan 8 at 4:41
add a comment |
In this post, I don't see 2.1 as listed format supported bylibfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC
– der_michael
Jan 8 at 4:41
In this post, I don't see 2.1 as listed format supported by
libfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC– der_michael
Jan 8 at 4:41
In this post, I don't see 2.1 as listed format supported by
libfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC– der_michael
Jan 8 at 4:41
add a comment |
1 Answer
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libfdk_aac doesn't support the 2.1 channel layout:
$ ffmpeg -h encoder=libfdk_aac
[...]
Encoder libfdk_aac [Fraunhofer FDK AAC]:
Supported channel layouts: mono stereo 3.0 4.0 5.0 5.1 7.1(wide) 7.1
You'll have to use a supported layout or use a different encoder instead, such as -c:a aac as you mentioned.
answered Jan 10 at 18:03
lloganllogan
25.4k54679
add a comment |
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libfdk_aac doesn't support the 2.1 channel layout:
$ ffmpeg -h encoder=libfdk_aac
[...]
Encoder libfdk_aac [Fraunhofer FDK AAC]:
Supported channel layouts: mono stereo 3.0 4.0 5.0 5.1 7.1(wide) 7.1
You'll have to use a supported layout or use a different encoder instead, such as -c:a aac as you mentioned.
answered Jan 10 at 18:03
lloganllogan
25.4k54679
add a comment |
libfdk_aac doesn't support the 2.1 channel layout:
$ ffmpeg -h encoder=libfdk_aac
[...]
Encoder libfdk_aac [Fraunhofer FDK AAC]:
Supported channel layouts: mono stereo 3.0 4.0 5.0 5.1 7.1(wide) 7.1
You'll have to use a supported layout or use a different encoder instead, such as -c:a aac as you mentioned.
answered Jan 10 at 18:03
lloganllogan
25.4k54679
add a comment |
libfdk_aac doesn't support the 2.1 channel layout:
$ ffmpeg -h encoder=libfdk_aac
[...]
Encoder libfdk_aac [Fraunhofer FDK AAC]:
Supported channel layouts: mono stereo 3.0 4.0 5.0 5.1 7.1(wide) 7.1
You'll have to use a supported layout or use a different encoder instead, such as -c:a aac as you mentioned.
answered Jan 10 at 18:03
lloganllogan
25.4k54679
libfdk_aac doesn't support the 2.1 channel layout:
$ ffmpeg -h encoder=libfdk_aac
[...]
Encoder libfdk_aac [Fraunhofer FDK AAC]:
Supported channel layouts: mono stereo 3.0 4.0 5.0 5.1 7.1(wide) 7.1
You'll have to use a supported layout or use a different encoder instead, such as -c:a aac as you mentioned.
answered Jan 10 at 18:03
lloganllogan
25.4k54679
answered Jan 10 at 18:03
lloganllogan
25.4k54679
answered Jan 10 at 18:03
lloganllogan
25.4k54679
answered Jan 10 at 18:03
lloganllogan
25.4k54679
25.4k54679
add a comment |
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In this post, I don't see 2.1 as listed format supported by
libfdk_aac: wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC– der_michael
Jan 8 at 4:41