[FFmpeg-user] MP4s (and M4As) for music

[Mark Filipak]

Here's my latest script. It makes aac-in-m4a

ffmpeg^
  -i "c:\chapters.txt"^
  -i c:\01.WAV^
  -i c:\02.WAV^
  -i c:\03.WAV^
  -i c:\04.WAV^
  -i c:\05.WAV^
  -i c:\06.WAV^
  -i c:\07.WAV^
  -i c:\08.WAV^
  -filter_complex "[1:0][2:0][3:0][4:0][5:0][6:0][7:0][8:0]concat=n=8:v=0:a=1[out]"^
  -map_metadata 0 -map "[out]"^
  -c aac -b:a 657.6k^
  "c:\Ashra, Belle Alliance [1980].m4a"

The aac-in-m4a is 125,341,168 bytes. It sounds much smoother than mp3-in-mp4.
The mp3-in-mp4 using lame was 42,705,917 bytes.
8 wav files total 466,343,152 bytes.

The script above provoked this: "Too many bits 15269.442177 > 12288 per frame requested, clamping to 
max". Of course, I have no idea what that's about. Do you? "Too many bits"?

I just downloaded this:
https://www.videohelp.com/software/MP4Box

I've read that mp4box will package pcm-in-mp4. I don't know anything else about it yet. It's not a 
big deal since aac-in-m4a (above) is so good.

--Mark.