使用Gstreamer-1.0编码G722遇SIGSEGV错误，求解决方案

Let's break down your problem step by step and fix this SIGSEGV issue, plus explore better encoder options for G722 on your iMX6ULL/Yocto Morty setup.

1. Fix Your Pipeline First (This Is Likely Causing the Crash) #

Your original command includes decodebin right after alsasrc—that's a critical mistake! alsasrc outputs raw PCM audio, not a compressed format that needs decoding. Throwing decodebin at raw audio confuses the pipeline, which is almost certainly triggering the SIGSEGV.

Replace your send command with this cleaned-up version:

gst-launch-1.0 -v alsasrc device="hw:0" ! audioconvert ! audioresample ! avenc_g722 ! fakesink

Even better, G722 natively expects 16kHz sampling rate, mono audio (it's designed for 7kHz bandwidth speech). Forcing these parameters upfront reduces unnecessary conversion and can boost stability:

gst-launch-1.0 -v alsasrc device="hw:0" ! audio/x-raw, rate=16000, channels=1 ! audioconvert ! audioresample ! avenc_g722 ! fakesink

2. Address the ALSA Xrun Warning #

The Broken pipe xrun error suggests your ALSA device is underrunning. You can mitigate this by adding a larger buffer to alsasrc to give more headroom for audio processing on the iMX6ULL:

gst-launch-1.0 -v alsasrc device="hw:0" buffer-time=200000 ! audio/x-raw, rate=16000, channels=1 ! audioconvert ! audioresample ! avenc_g722 ! fakesink

The buffer-time=200000 sets a 200ms buffer, which should reduce underrun issues.

3. Alternative G722 Encoders (More Stable Than avenc_g722 on Older Platforms) #

Yes, avenc_g722 (from gst-libav) has had stability bugs on ARM platforms like the iMX6ULL, especially in the older versions bundled with Yocto Morty. Try these more reliable alternatives:

Option 1: g722enc (GStreamer's Official Encoder)

This encoder is part of gst-plugins-good—check if your Yocto image includes this plugin (it should by default, but if not, add gst-plugins-good to your build recipe). It's maintained directly by the GStreamer team and tends to be more stable on embedded ARM:

gst-launch-1.0 -v alsasrc device="hw:0" ! audio/x-raw, rate=16000, channels=1 ! audioconvert ! audioresample ! g722enc ! fakesink

Option 2: Updated avenc_g722 (If You Can Patch/Upgrade)

You mentioned thinking ffenc_g722 was only for GStreamer 0.10—you're right about that, but for GStreamer 1.x, FFmpeg's G722 encoder is wrapped in avenc_g722 via the gst-libav plugin. If you can't switch to g722enc, try updating gst-libav or applying ARM-specific patches to the FFmpeg version in your Yocto build to fix the crash.

4. Debugging the SIGSEGV Further #

If you still hit crashes after fixing the pipeline, use GDB to get a meaningful stack trace (your initial GDB output only showed the poll() call, which isn't helpful):

1. Run gdb gst-launch-1.0
2. Inside GDB, start your pipeline with:

   run -v alsasrc device="hw:0" ! audio/x-raw, rate=16000, channels=1 ! audioconvert ! audioresample ! avenc_g722 ! fakesink
   

3. When the crash happens, run bt to print the full backtrace. This will show exactly which function (in avenc_g722, ALSA, or another plugin) is causing the segmentation fault, making it easier to report or fix the bug.

内容的提问来源于stack exchange，提问作者user8257918