How to decode MP3 using libmp3lame decoder using ffmpeg command line? - ffmpeg

I need to decode .mp3 file using libmp3lame decoder in ffmpeg, this ffmpeg build contains libmp3lame. Decoded output can be .wav/.raw format.So can anyone help me how to decode this using ffmpeg command line.I'm using windows 8.1 os.

Why not use LAME directly, since you are relying on the libmp3lame anyways?.. as in
LAME.EXE --decode myfile.mp3 myfile.wav

Related

How to decode G.729b codec?

I am developing an application that listens for RTP data using GStreamer and converts the received raw data packets using FFMPEG.
I works well for codes: PCMA, PCMU, G722 and G729 and converts the received audio files into wav and mp3. But the conversion fails when G729b packet is received. FFMPEG has support for G729 as mentioned here but nothing is mentioned about G729a/b. GStreamer also has not mentioned anything about G729a/b though has a decoder for G729. I also didn't find any other library that can convert G729b to wav or mp3.
Can anyone please suggest any way or any library to convert G729a/b to wav.
Thanks in advance!
Command used:
ffmpeg -f g729 -i .g729 -acodec pcm_s16le -ar 8000 output.wav
Please find the two files here

ffmpeg fails to Play Proxy Avid Interplay

My goal is transcode this file with ffmpeg.
https://drive.google.com/open?id=1ATuPtSbZeQLexB1HBP509hInDOTyfEV8
ffplay fails to analize or play this file and returns:
Invalid pixel format.
This is the simply command:
ffplay -i testproxy.mxf
ffprobe -i testproxy.mxf -show_stream
It has been encoded by avid Interplay whit this targhet quality:
H.264 800Kbps Proxy 1080i 25
Maybe it's a raw file? and need same specification ahead input file?
Any suggestion is appreciated
Either Interplay doesn't write* a standard MXF or there's a limitation in ffmpeg's mxf demuxer.
But you can play the file with
ffplay -vcodec h264 testproxy.mxf
and similarly, you can transcode using
ffmpeg -vcodec h264 -i testproxy.mxf ...
*more likely, as mediainfo also fails to detect the video codec.

Stretching WAV audio file with rubberband in fffmpeg causes invalid audio format

Having an issue here using ffmpeg's add-on Rubberband. When I try to stretch a WAV audio file with a given ratio, the WAV file is generated fine but then, when I want to parse its header, I can see an invalid audio format.
'Unknwon format: 22127'
Have reported this issue on this GitHub tracker. All details are there:
https://github.com/rackfx/Node-WAV-File-Info/issues/11
But now I am very unsure and wonder if it's not a Rubberband bug? Or am I missing something in the ffmpeg command to ensure correct audio format is set?
That's the ffmpeg command I used to generate that stretched WAV file with the invalid audio format (using ffmpeg v3.0.2 here)
ffmpeg -thread_queue_size 2048 -i /home/michael-heuberger/binarykitchen/code/videomail.io/var/local/tmp/clients/videomail.io/11e6-aebd-f5430180-84c7-074d5706928b/videomail_preview.wav -y -acodec libvorbis -ac 1 -filter:a rubberband=tempo=1.454366279637038 -loglevel warning /home/michael-heuberger/binarykitchen/code/videomail.io/var/local/tmp/clients/videomail.io/11e6-aebd-f5430180-84c7-074d5706928b/videomail_preview_for_webm_stretched.wav
Any clues?
Remove -c:a libvorbis. ffmpeg will then automatically choose a common and compatible audio format for WAV.

How to pass options to ffmpeg from SoX?

I'm trying to combine and encode some files from wav to m4a. I installed both ffmpeg and sox from source to make sure nothing was disabled. When I do the conversion with ffmpeg
ffmpeg -i input.wav -acodec aac -strict experimental output.m4a
it works fine. When I use SoX
sox input.wav output.m4a
I get the error
[NULL # 0x251b4e0] Codec is experimental but experimental codecs are not enabled, see -strict -2
sox FAIL ffmpeg: ffmpeg could not open CODEC
sox FAIL formats: can't open output file `output.m4a':
I need to way to get SoX to tell ffmpeg that its ok to use the experimental codecs.
Also I already tried using this guide http://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide to install the fdk-acc encoder, but it didn't work. The experimental one works fine so I'd rather just use that.
I don't think sox supports m4a formats. you can do sox --help to see the audio file formats supported.

Use sox to combine audios

I have three 3gp file,and I use sox to combine them
sox --combine sequence C:\1.3gp C:\2.3gp C:\3.3gp C:\newaudio.3gp
but It's show that "FAIL formats:no handler for file extension 3gp"
Its means that I have to install some extension?
I'm trying to do it with sox,Can anybody give me any suggestions ?
Or It's possible do it with ffmpeg ?
3gp is a multimedia container and not supported by sox.
You can extract the audio with ffmpeg and further process it with sox although ffmpeg can also do a lot of audio processing.
Here's one way to convert the data to wav, concatenate and convert back to 3gp:
ffmpeg -i 1.3gp 1.wav
ffmpeg -i 2.3gp 2.wav
ffmpeg -i 3.3gp 3.wav
Concatenate, maybe other things with sox (sequence is default so no need to specify):
sox 1.wav 2.wav 3.wav long.wav
Convert back to 3gp:
ffmpeg -i long.wav newaudio.3gp

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