ffmpeg formula to convert any format to x264 video mp3 audio reencoding

[jraju]

Hi,
I have set of files of different video files having different video and audio contained in different containers like mp4, etc.
I want to convert the same files to x264 video and mp3 audio files using ffmpeg formula.
If there is a fast flag to recommend , this also be recommended.
Normally x264 supports aac audio, but I want it in mp3 audio format
plelase give me the solution

[jagabo]

Something like:

ffmpeg -i input.ext -map 0 -c:v libx264 -preset veryfast -crf 20 -ac 2 -c:a mp3 output.mkv

-i input.ext : specifies the input file
-map 0 : specifies all streams from the input file should be copied (including chapters, subtitles, etc., otherwise only video and audio will be copied)
-c:v libx264 : compress the video with x264
-preset veryfast : very fast encoding, not the greatest quality, others: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, placebo
-crf 20 : lower values give higher quality, bigger files; higher values give lower quality, smaller files
-ac 2 : convert audio to stereo (eg, downmix 5.1 to 2 channel stereo)
-c:a mp3 " encode the audio as mp3
-b:a 192k : the audio bitrate to use
output.mkv : the output filename, mkv container

[JKyle]

IMHO, it should be -c:a libmp3lame, not -c:a mp3.

[ProWo]

IMHO, it should be -c:a libmp3lame, not -c:a mp3.

-c:a mp3 is the intern mp3 encoder.

[jagabo]

Yes, libmp3lame is the better mp3 encoder. I can just never remember the name (I haven't used mp3 encoding in a long time).

[JKyle]

-c:a mp3 is the intern mp3 encoder.

AFAIK, there's only two mp3 encoders for a regular FFmpeg build: libmp3lame and mp3_mf. mp3 is a codec name, not an encoder name for a regular FFmpeg build such as BtbN's. But, yes, calling -c:a mp3 itself does not raise an error either because it calls libmp3lame internally.

[ProWo]

-c:a mp3 is the intern mp3 encoder.

AFAIK, there's only two mp3 encoders for a regular FFmpeg build: libmp3lame and mp3_mf. mp3 is a codec name, not an encoder name for a regular FFmpeg build such as BtbN's. But, yes, calling -c:a mp3 itself does not raise an error either because it calls libmp3lame internally.

Thx

[jagabo]

I tried a few different builds. With "-c:a mp3" one defaulted to libmp3lame, the other mp3_mf. So you probably want to specify which you want on the command line: "-c:a libmp3lame" or "-c:a mp3_mf". ffmpeg shows you which encoder it's using.

[jraju]

Hi, Jagabo, I used your formula . thanks.
mere mp3 did not proceed with some error.
i changed that part of libmp3lame and it is proceeding.
I have to check the time
while processing , it says q as 25, what does that mean
I checked the time , it is a time consuming, probably due to the reencoding.

[jraju]

Hi, today only I have seen a thread about handbrakecli, command line tool
Will that be faster Jagabo.
If so, kindly give the formula in handbrakecli
if not inform me please

[jagabo]

Handbrake uses the same x264 encoder as ffmpeg. So it's the same speed with the same settings.

[jagabo]

while processing , it says q as 25, what does that mean

That means the quantizer it's using at that time is 25.

[jraju]

Hi, Yes. Thanks for the reply.I also noticed that while processing ffmpeg command above, the fps changed on decreasing rate say 24 to 17, and I also noticed that q remains at 25. I think that 25 is the video frame rate which is constant at 25 as per the properties of the video.
what is this fps rate dcreasing on process. Is that the processsing frame rate and nothing to do with the constant rate or, the video has different fps , variable rate, in the entire video.
This is to knowsomething

[jagabo]

Here's an example status line:

frame= 2302 fps=656 q=25.0 size=    5376kB time=00:01:33.59 bitrate= 470.5kbits/s speed=26.7x

I believe this is what each value means:

"frame= 2302" is the current frame being processed.

"fps=656" is the average rate at which it is encoding frames, so far.

"q=25.0" With bitrate encoding it is the average quantizer, so far. I'm not sure exactly what it means with crf encoding (it remains constant).

"size= 5376kB" is the current size of the output file.

"time=00:01:33.59" is the timestamp of the frame currently being processed.

"bitrate= 470.5kbits/s" this is the average bitrate, so far.

"speed=26.7x" is the average encoding speed relative to real time, so far. For example, a 30fps video encoding at 60 fps is encoding at 2x real time.

[jraju]

Hi, thanks . Command line takes a lot of time compared to converters , it seems.

[jagabo]

Hi, thanks . Command line takes a lot of time compared to converters , it seems.

No. Speed of all the free editor/encoders are about the same -- as they all use the same encoders (x264, x265, nvenc, qsv...). It all depends on which encoder and the settings you use.