vaapi_encode_mjpeg: fix bad component id bug

The compound literals assigned to "components"
only exist within the scope of the if/else
block (thanks Mark Thompson for the better
explanation).

Thus, after this if/else block, "components"
ends up pointing to an arbitrary/undefined
array.  With some compilers and depending on
optimization settings, these arbitrary values
may end up being the same value (i.e. 0 with
GNU GCC 9.x).  Unfortunately, the GNU GCC
compiler, at least, never prints any warnings
about this.

This patch fixes this issue by assigning the
constant arrays to local variables at function
scope and then pointing "components" to those
as necessary.

Fixes #7915

Signed-off-by: U. Artie Eoff <ullysses.a.eoff@intel.com>

diff --git a/libavcodec/vaapi_encode_mjpeg.c b/libavcodec/vaapi_encode_mjpeg.c
index 4dcdc3d16bb0a9eac3b41e0e4d9dfe3aedbd56fa..bd029cc90315e1e224802b5225d86d77f3dfbac7 100644 (file)
--- a/libavcodec/vaapi_encode_mjpeg.c
+++ b/libavcodec/vaapi_encode_mjpeg.c
@@ -227,6 +227,8 @@ static int vaapi_encode_mjpeg_init_picture_params(AVCodecContext *avctx,
     JPEGRawScanHeader                 *sh = &priv->scan.header;
     VAEncPictureParameterBufferJPEG *vpic = pic->codec_picture_params;
     const AVPixFmtDescriptor *desc;
+    const uint8_t components_rgb[3] = { 'R', 'G', 'B' };
+    const uint8_t components_yuv[3] = {  1,   2,   3  };
     const uint8_t *components;
     int t, i, quant_scale, len;
 
@@ -235,9 +237,9 @@ static int vaapi_encode_mjpeg_init_picture_params(AVCodecContext *avctx,
     desc = av_pix_fmt_desc_get(priv->common.input_frames->sw_format);
     av_assert0(desc);
     if (desc->flags & AV_PIX_FMT_FLAG_RGB)
-        components = (uint8_t[3]) { 'R', 'G', 'B' };
+        components = components_rgb;
     else
-        components = (uint8_t[3]) {  1,   2,   3  };
+        components = components_yuv;
 
     // Frame header.