capture.cpp aborting libv4l2 JPEG header error

[mrazjava]

This issue is more directly OpenIMAJ but you might want to consider fixing capture.cpp to gracefully handle a common linux v4l error. With my Dell inspiron 1545, Ubuntu 10.04, OpenIMAJGrabber aborts causing program shutdown when libv4l encounters the folliowing:

libv4l2: error converting / decoding frame data: v4l-convert: error parsing JPEG header: Not a JPG file ?

This is a common linux issue with some webcams, but capture.cpp is falling through into error exit rather than ignoring the error:

    case IO_METHOD_MMAP:
            CLEAR (buf);

            buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
            buf.memory = V4L2_MEMORY_MMAP;

            if (-1 == xioctl (grabber->fd, VIDIOC_DQBUF, &buf)) {

                    switch (errno) {
                    case EAGAIN:
                            return 0;

                    case EIO:
                            /* Could ignore EIO, see spec. */
                            /* fall through */

                    default:
                            errno_exit ("VIDIOC_DQBUF");
                    }
            }

I fixed it by recompiling native lib (for linux only) with simple return 0 under case EIO:

                    case EIO:
                            /* Could ignore EIO, see spec. */
            return 0;
                            /* fall through */

This took care of the problem. Again, not affecting me directly since I've rebuilt mine but to save other linux user a headache you might want to recompile with return 0.

[sarxos]

Yeah, those are the most nasty bugs ;] Thank you for finding it! I will probably fork OpenIMAJ native code and take a look on it, but in the meantime, could you also, if that's not a problem, open a ticket in OpenIMAJ project? Their JIRA can be found here.

Just for my memory I'm putting a link to the capture.cpp file here.

[sarxos]

OpenIMAJ issue OP-41 is fixed. Waiting for OP-44.

[sarxos]

Issue OP-44 will be integrated in separate commit.

[He-Pin]

wow~~!nice
i am handling the udt android porting ...

[sarxos]

Those files will be integrated into 0.3.7:

• Linux 32-bit binaries
• Linux 64-bit binaries
• Linux ARM 32-bit binaries