| Message ID | 20190607214137.20333-1-ullysses.a.eoff@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
> -----Original Message----- > From: Eoff, Ullysses A > Sent: Friday, June 07, 2019 2:42 PM > To: ffmpeg-devel@ffmpeg.org > Cc: Eoff, Ullysses A <ullysses.a.eoff@intel.com> > Subject: [PATCH v3] 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 Mike Thompson for the better Oh crap, I got your name wrong. It must be a Friday! V4 coming up! > 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> > --- > libavcodec/vaapi_encode_mjpeg.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/libavcodec/vaapi_encode_mjpeg.c b/libavcodec/vaapi_encode_mjpeg.c > index 4dcdc3d16bb0..bd029cc90315 100644 > --- 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. > > -- > 2.20.1
diff --git a/libavcodec/vaapi_encode_mjpeg.c b/libavcodec/vaapi_encode_mjpeg.c index 4dcdc3d16bb0..bd029cc90315 100644 --- 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.
The compound literals assigned to "components" only exist within the scope of the if/else block (thanks Mike 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> --- libavcodec/vaapi_encode_mjpeg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)