[FFmpeg-devel] SDR choices

[Cosmin Stejerean]

> On Sep 26, 2023, at 11:14 AM, Anton Khirnov <anton at khirnov.net> wrote:
> 
> From my perspective, the objections to SDR have been largely
> technical,

From my perspective the objections against the current SDR implementation could be grouped into roughly 3 categories:

A) support for taking input from an SDR device doesn't belong in ffmpeg at all in any form, it's way too big and there are other projects out there for SDR there that one ought to use instead, and trying to do it in ffmpeg in any form would bloat the codebase and make a mess no matter which option is chosen

B) support for SDR is fine to have in ffmpeg, but it should be done via an external library that does not live in the ffmpeg source tree, and ffmpeg could be optionally compiled with a --enable-libsdr or some such

C) support for SDR is fine to have as long as it's in a separate module like a libavradio with a clean API rather than trying to beat it into libavdevice, the current implementation is too invasive

All 3 are united in objecting to the current implementation, which I'd summarize as SDR using libavdevice (let's call it option D). This makes it seem like there's a united front against SDR, but I think there's significant disagreement even among the people objecting to the current implementation as to which one of these 3 ought to be the right outcome for SDR. The discussion tends to go in circles. Discussions about C-vs-D tend to run into objections from B, trying to discuss the relative merits of B-vs-C runs into objections from A and so on.

This might be a good use of the TC (after a new GA and new TC is formed to avoid arguments about the validity of the decision). The TC could then settle on the direction for SDR in the project:

A. no SDR in ffmpeg at all
B. SDR via external library
C. SDR via a new libavradio library
D. SDR via libavdevice

For what it's worth as a user of ffmpeg I hope the outcome is not A, I believe having support for RTL-SDR in ffmpeg would be neat and I'd love to use it (at home, at work I'd compile ffmpeg with SDR disabled). I'm not qualified to comment on whether B,C or D are better ways to achieve it.

- Cosmin