vid: remove pixel formats RGB555 and RGB565

[alfredh]

proposal to remove pixel formats with low bit depth

[juha-h]

I was using VID_FMT_RGB565 in my Android app. With what format should I replace it?

[juha-h]

I tried with VID_FMT_RGB32 and VID_FMT_YUV444P. With VID_FMT_RGB32 there was colorful garbage on the screen and with VID_FMT_YUV444P screen stayed black. Please bring the removed format back unless a working alternative is found.

The code where I use the format goes like this:

int opengles_display(struct vidisp_st *st, const char *title, const struct vidframe *frame, uint64_t timestamp)
{
    (void)title;
    (void)timestamp;
    int err;

    /* This is hack to make sure that context is initialised on the same thread */
    if (!st->context) {
        err = context_initialize(st);
        if (err) {
            LOGW("Renderer context init failed with error %d\n", err);
            return err;
        }
    }

    if (!st->vf) {
        if (frame->size.w & 3) {
            LOGW("opengles_display: frame width must be multiple of 4\n");
            return EINVAL;
        }

        err = vidframe_alloc(&st->vf, VID_FMT_RGB565, &frame->size);
        if (err) {
            LOGW("opengles_display: vidframe_alloc failed\n");
            return err;
        }
    }

    vidconv(st->vf, frame, NULL);

    opengles_render(st);

    err = eglSwapBuffers(st->display, st->surface);
    if (!err)
        LOGW("eglSwapBuffers() returned error %s\n", egl_error(eglGetError()));

    return err;
}

[juha-h]

Tried all formats bpp >= 16 and all of them failed to work. Either colorful garbage or black screen.

[juha-h]

With VID_FMT_YUV444P I get errors:

03-12 11:38:58.176  3737  3805 D Baresip+ Lib: vidconv: no pixel converter found for yuv420p -> yuv444p

And with VID_FMT_YUV420P I see the screen split into 4 colorful garbage rectangles.

[sreimers]

Looks like these are the only supported formats on android:

https://developer.android.com/reference/android/graphics/Bitmap.Config

If I interpret the documention correctly the prefered one is:

https://developer.android.com/reference/android/graphics/Bitmap.Config#ARGB_8888

https://developer.android.com/reference/android/graphics/Bitmap.Config#RGB_565
Says This configuration can produce slight visual artifacts depending on the configuration of the source

[sreimers]

Can you try VID_FMT_ARGB?

[juha-h]

With VID_FMT_ARGB I get black screen and lots of these to log:

03-12 13:22:02.818  6879  6975 D Baresip+ Lib: vidconv: no pixel converter found for yuv420p -> argb
03-12 13:22:02.854  6879  6975 D Baresip+ Lib: vidconv: no pixel converter found for yuv420p -> argb
03-12 13:22:02.869  6879  6975 D Baresip+ Lib: vidconv: no pixel converter found for yuv420p -> argb

Am I missing some module that does the conversion?

[sreimers]

I see, we have no conversion function:

https://github.com/baresip/rem/blob/main/src/vidconv/vconv.c#L644-L661

[juha-h]

So best would be to add support for ARGB_8888 or (if it takes long or cannot be done at all) restore support for VID_FMT_RGB565.

[juha-h]

There has been reports on the net that ARGB_8888 performance can be very bad. So better to stick to VID_FMT_RGB565.