Can anyone suggest me what audio and video codecs allows me to retain frequencies above 18khz till 22050hz in the resultant mp4 or avi video with out any filters.
No limit for size and HD is preferred.
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Although there are other variables, the key factor is to make sure the sample rate is more than twice the highest frequency you want to preserve. – Bjorn Roche Jun 25 '13 at 13:55
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yeah I made sure sampling rate is 44100+, even then i couldnt find any frequency above 16khz in the resultant Mp4's audio – RaviTejas3 Jun 26 '13 at 06:26
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AAC encoders supports frequencies up to 96000 Hz. ("libfdk_aac", "aac", "libvo_aacenc" codecs)
UPD
I took a lossless compressed audio as the source.
See its spectrum
I recoded it with the video using ffmpeg.
ffmpeg -t 10 -i 01.mp4 -t 10 -i Wait.m4a -ar 48000 -ab 320k -c:a aac -strict -2 Wait.mp4
The spectrum of the audio in the resulting file.
pogorskiy
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but when I use $ffmpeg -i video.mp4 -i audio.wav -c:a libfdk_aac out.mp4 the resultant video doesnt contain any freq greater than 16Khz – RaviTejas3 Jun 25 '13 at 09:01
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Try `$ffmpeg -i video.mp4 -i audio.wav -c:a libfdk_aac -sample_rate 96000 out.mp4` – pogorskiy Jun 25 '13 at 09:14
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If you're talking about cutting the frequency you may be sure that the original audio has a larger range. – pogorskiy Jun 25 '13 at 11:18
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Yeah am very sure that original audio file has freq till 20khz. I use spek to get the spectrum. – RaviTejas3 Jun 25 '13 at 11:22
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1. I wrote wrong setting (sample_rate), use `-ar 96000` options instead. 2. Try to increase audio bitrate (`-ab 360k`) 3. Most players will not play files with a high sampling rate, so use `-ar 48000`. – pogorskiy Jun 25 '13 at 12:33
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Used your setting and still i face the same problem.Is it the problem with video that cant hold audio in its container? – RaviTejas3 Jun 26 '13 at 06:23
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