[Mesa-dev] [PATCH v2 6/7] egl/android: Add support for YV12 pixel format (v2)

[Rob Herring]

On Mon, Aug 8, 2016 at 1:39 PM, Chad Versace <chad at kiwitree.net> wrote:
> On 08/02/2016 04:07 AM, Tomasz Figa wrote:
>>
>> This patch adds support for YV12 pixel format to the Android platform
>> backend. Only creating EGL images is supported, it is not added to the
>> list of available visuals.
>>
>> v2: Use const array defined just for YV12 instead of trying to be overly
>>     generic.
>>
>> Signed-off-by: Tomasz Figa <tfiga at chromium.org>
>> Signed-off-by: Kalyan Kondapally <kalyan.kondapally at intel.com>
>> ---
>>  src/egl/drivers/dri2/platform_android.c | 56
>> +++++++++++++++++++++++++++++----
>>  1 file changed, 50 insertions(+), 6 deletions(-)
>
>
>
>
>> @@ -512,22 +518,60 @@ static _EGLImage *
>>  droid_create_image_from_prime_fd(_EGLDisplay *disp, _EGLContext *ctx,
>>                                   struct ANativeWindowBuffer *buf, int fd)
>>  {
>> +   unsigned int offsets[3] = { 0, 0, 0 };
>> +   unsigned int pitches[3] = { 0, 0, 0 };
>> +
>>     const int fourcc = get_fourcc(buf->format);
>> -   const int pitch = buf->stride * get_format_bpp(buf->format);
>> +   if (fourcc == -1) {
>> +      _eglError(EGL_BAD_PARAMETER, "eglCreateEGLImageKHR");
>> +      return NULL;
>> +   }
>>
>> -   const EGLint attr_list[14] = {
>> +   pitches[0] = buf->stride * get_format_bpp(buf->format);
>> +   if (pitches[0] == 0) {
>> +      _eglError(EGL_BAD_PARAMETER, "eglCreateEGLImageKHR");
>> +      return NULL;
>> +   }
>> +
>> +   switch (buf->format) {
>> +   case HAL_PIXEL_FORMAT_YV12:
>> +      /* Y plane is assumed to be at offset 0. */
>> +      /* Cr plane is located after Y plane */
>> +      offsets[1] = offsets[0] + pitches[0] * buf->height;
>> +      pitches[1] = ALIGN(pitches[0] / 2, 16);
>> +      /* Cb plane is located after Cr plane */
>> +      offsets[2] = offsets[1] + pitches[1] * buf->height / 2;
>
>
> I believe the above should be
>    offsets[2] = offsets[1] + pitches[1] * ALIGN(buf->height, 2) / 2;
> to accommodate buffers with odd height.

Android defines this format is even height and width with a stride
multiple of 16 pixels:

    /*
     * Android YUV format:
     *
     * This format is exposed outside of the HAL to software decoders and
     * applications.  EGLImageKHR must support it in conjunction with the
     * OES_EGL_image_external extension.
     *
     * YV12 is a 4:2:0 YCrCb planar format comprised of a WxH Y plane followed
     * by (W/2) x (H/2) Cr and Cb planes.
     *
     * This format assumes
     * - an even width
     * - an even height
     * - a horizontal stride multiple of 16 pixels
     * - a vertical stride equal to the height
     *
     *   y_size = stride * height
     *   c_stride = ALIGN(stride/2, 16)
     *   c_size = c_stride * height/2
     *   size = y_size + c_size * 2
     *   cr_offset = y_size
     *   cb_offset = y_size + c_size
     *
     * When used with ANativeWindow, the dataSpace field describes the color
     * space of the buffer.
     */

Rob