Media Resource Could Not Be Decoded in Firefox

[Marco77577]

I am using jmuxer in Chrome and it works perfectly fine.

On Firefox, however, I get the following warnings in the console, while the image is black or you can see a single frame at a time at best.

Media resource blob:http://localhost:4200/f0d9d5dc-148e-4bb5-93ab-c7c0fb44f7eb could not be decoded.

Media resource blob:http://localhost:4200/f0d9d5dc-148e-4bb5-93ab-c7c0fb44f7eb could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_DECODE_ERR (0x806e0004)
Details: virtual mozilla::MediaResult mozilla::FFmpegVideoDecoder<58>::DoDecode(mozilla::MediaRawData *, uint8_t *, int, bool *, MediaDataDecoder::DecodedData &): avcodec_send_pac

Do you know why this could be happening? Why does it work on Chrome, but not on Firefox?

Do you need any more information from me to solve this?

[chrivers]

I'm seeing the same problems - working in chrome, not working in firefox. And those same log messages.

[Marco77577]

I am also still interested in any insight the developer could shed on this.

[chrivers]

I figured out the cause! (At least for my installation).

I've installed firefox from Flatpak, and I hadn't installed the full codec pack to go along with it, so h264 support was actually broken across my firefox installation.

Running flatpak install org.freedesktop.Platform.ffmpeg-full + restarting firefox fixed it.

If you have this issue, I highly recommend you start by verifying that h264 works in your browser at all.