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Is there a way to convert MPEG-2 Layer 3 audio to MPEG-1 Layer 3 audio?
I've tried to search for such a tools on internet but none of them does this explicitly.
lang2
Posted 2013-09-12T08:31:09.023
Reputation: 1 830
Converting MPEG-2 Layer 3 to MPEG-1 Layer 3 audio
Answers
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There's virtually no difference between MPEG-1 Layer III (ISO/IEC 11172-3) and MPEG-2 Layer III (ISO/IEC 13818-3), other than the supported bit rates and sample rates.
The sample rates are mutually exclusive between those two. MPEG-1 allows 32, 48 and 44.1 kHz, while MPEG-2 allows 16, 24 and 22.05 kHz. The (inofficial) MPEG-2.5 allows 8, 12 and 11.025 kHz.
The LAME MP3 encoder will automatically choose the right standard depending on the sample rate (or bit rate):
lame in.wav --resample 32000 out-32.mp3
Resampling: input 44.1 kHz output 32 kHz
Encoding as 32 kHz j-stereo MPEG-1 Layer III (10.7x) 96 kbps qval=3
lame in.wav --resample 24000 out-24.mp3
Resampling: input 44.1 kHz output 24 kHz
Encoding as 24 kHz j-stereo MPEG-2 Layer III (12x) 64 kbps qval=3
lame in.wav --resample 12000 out-12.mp3
Resampling: input 44.1 kHz output 12 kHz
Encoding as 12 kHz j-stereo MPEG-2.5 Layer III (12x) 32 kbps qval=3
slhck
Posted 2013-09-12T08:31:09.023
Reputation: 182 472
I think most conversion tools can do this. For example
ffmpegcan be used to make mp3 files from a wide variety of input formats. – Tim – 2013-09-12T08:39:32.7532You do realize that there's virtually no difference between MPEG-1 Layer III (ISO/IEC 11172-3) and MPEG-2 Layer III (ISO/IEC 13818-3)? That's two names for the same technical thing—MPEG-2 only has different bit rates and sample rates available. What are you really trying to accomplish? – slhck – 2013-09-12T09:01:47.107
@slhck I'm not very clear on that. I can see that the version field in frame header will be different. Is that the only difference? – lang2 – 2013-09-12T11:08:43.663