Unexpected FLV instead of H264 on 1.10.11/Debian12

We have been running 1.10.10/Debian11 with no problems, but when we tried 1.10.11/Debian12 the video codec was unexpectedly FLV instead of H.264.

We’re going to partially revert to 1.10.11/Debian11 but we’d like to know if there’s a solution for Debian12.

What are the steps to replicate this? More information is needed please.

This is what we see in the logs on Debian11:
avformat.c:3340 use video codec implementation Video: h264 (libx264), yuv420p(pc, gbr/unknown/unknown), 320x240, q=-1–1, 81 kb/s

This is on Debian12:
avformat.c:3340 use video codec implementation Video: flv1 (flv), yuv420p(pc, gbr/unknown/unknown), 320x240, q=2-31, 81 kb/s

The cause seems to be a change in the way the preprocessor directives are being processed when we compile avformat.c on Debian12. In previous versions,


has been true, but since the upgrade to libavformat59 on Debian12, that’s not the case anymore.

To replicate it, you could add this

switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, “Expected output.\n”);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, “Unexpected output.\n”);

at line 3493, and compile on both versions of Debian.