[PATCH v4 14/36] [media] v4l2-mc: add a function to inherit controls from a pipeline
From: Pavel Machek <hidden>
Date: 2017-03-10 21:55:34
Also in:
linux-devicetree, linux-media, lkml
Hi!
Argh! that is indeed a bug at libv4l (and maybe at gstreamer).
I guess that the always_needs_conversion logic was meant to be used to
really odd proprietary formats, e. g:
/* Vendor-specific formats */
#define V4L2_PIX_FMT_CPIA1 v4l2_fourcc('C', 'P', 'I', 'A') /* cpia1 YUV */
#define V4L2_PIX_FMT_WNVA v4l2_fourcc('W', 'N', 'V', 'A') /* Winnov hw compress */
#define V4L2_PIX_FMT_SN9C10X v4l2_fourcc('S', '9', '1', '0') /* SN9C10x compression */
...
I suspect that nobody uses libv4l2 with MC-based V4L2 devices. That's
likely why nobody reported this bug before (that I know of).
In any case, for non-proprietary formats, the default should be to
always offer both the emulated format and the original one.
I suspect that the enclosed patch should fix the issue with bayer formats....
quoted hunk ↗ jump to hunk
@@ -178,7 +178,7 @@ struct v4lconvert_data *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri /* This keeps tracks of devices which have only formats for which apps most likely will need conversion and we can thus safely add software processing controls without a performance impact. */ - int always_needs_conversion = 1; + int always_needs_conversion = 0; if (!data) { fprintf(stderr, "libv4lconvert: error: out of memory!\n");@@ -208,8 +208,8 @@ struct v4lconvert_data *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri if (j < ARRAY_SIZE(supported_src_pixfmts)) { data->supported_src_formats |= 1ULL << j; v4lconvert_get_framesizes(data, fmt.pixelformat, j); - if (!supported_src_pixfmts[j].needs_conversion) - always_needs_conversion = 0; + if (supported_src_pixfmts[j].needs_conversion) + always_needs_conversion = 1; } else always_needs_conversion = 0; }
Is the else still needed? You changed default to 0... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 181 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20170310/9f4e10d8/attachment-0001.sig>