[FFmpeg-devel] Add on-the-fly bitrate adjustment for encoding

[Moritz Barsnick]

On Thu, Oct 10, 2019 at 09:24:08 -0700, Adrian Cable wrote:
> This is an addition to ffmpeg.c which enables on-the-fly encoder (e.g. H.264) bitrate adjustment using ffmpeg interactive mode. For example, specify “-b:v 299k -bufsize 299k” on the command line to start encoding at 299kbit/sec, then to adjust the encoder bitrate to 200kbit/sec during encoding, type:

Just from a quick attempt and check:
- Doesn't prompt properly like the other commands do. (Did you model
  the code against those implementations? I didn't compare.) I think
  the input "prompt" appears on top of the default progress output,
  which is highly confusing.
- Doesn't parse bitrates like the command line does (e.g. "3M"). I
  believe the command line uses av_strtod().
- What are the side effects? Will metadata be incorrect?
- Documentation is missing.

Cheers,
Moritz