[FFmpeg-devel] [PATCH] avfilter: add dumpwave filter.

[Tobias Rapp]

On 08.01.2018 01:36, dmitry.gumenyuk at gmail.com wrote:
> From: Dmytro Humeniuk <dmitry.gumenyuk at gmail.com>
> 
> Signed-off-by: Dmytro Humeniuk <dmitry.gumenyuk at gmail.com>
> ---
>   Changelog                      |   1 +
>   libavfilter/Makefile           |   1 +
>   libavfilter/af_dumpwave.c      | 273 +++++++++++++++++++++++++++++++++++++++++
>   libavfilter/allfilters.c       |   1 +
>   libavfilter/version.h          |   4 +-
>   tests/fate/filter-audio.mak    |   5 +
>   tests/ref/fate/filter-dumpwave |   1 +
>   7 files changed, 284 insertions(+), 2 deletions(-)
>   create mode 100644 libavfilter/af_dumpwave.c
>   create mode 100644 tests/ref/fate/filter-dumpwave
> 
> [...]

As far as I can see the filter reads audio and writes an envelope curve 
using JSON data format. The JSON data is then rendered into an image 
outside of FFmpeg.

In my opinion it would be better to allow connecting the filter with 
other filters by directly rendering the image within FFmpeg. So the 
filter should have a generic video output instead of the JSON output. 
This would be similar to the existing "showvolume" filter.

If you just want to get the raw envelope data from FFmpeg I suggest to 
take a look at the "write_peak" option of the WAV muxer.

Regards,
Tobias