[FFmpeg-cvslog] avcodec/libjxldec: fix gamma22 and gamma28 recognition

[Leo Izen]

ffmpeg | branch: master | Leo Izen <leo.izen at gmail.com> | Wed Jan 18 09:16:37 2023 -0500| [9d5e66942c5bae578926e29efebec348199798df] | committer: Jan Ekström

avcodec/libjxldec: fix gamma22 and gamma28 recognition

Gamma 2.2 and Gamma 2.8 are tagged in the file as 0.45455 and 0.35714,
respectively (i.e. 1/2.2 and 1/2.8). Trying to identify them as 2.2 and
2.8 instead of these values will cause the transfer function to not
properly be recognized. This patch fixes this.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9d5e66942c5bae578926e29efebec348199798df
---

 libavcodec/libjxldec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/libjxldec.c b/libavcodec/libjxldec.c
index de48bea4b2..c85cfa3d69 100644
--- a/libavcodec/libjxldec.c
+++ b/libavcodec/libjxldec.c
@@ -167,9 +167,9 @@ static enum AVColorTransferCharacteristic libjxl_get_trc(void *avctx, const JxlC
     case JXL_TRANSFER_FUNCTION_DCI: return AVCOL_TRC_SMPTE428;
     case JXL_TRANSFER_FUNCTION_HLG: return AVCOL_TRC_ARIB_STD_B67;
     case JXL_TRANSFER_FUNCTION_GAMMA:
-        if (jxl_color->gamma > 2.199 && jxl_color->gamma < 2.201)
+        if (jxl_color->gamma > 0.45355 && jxl_color->gamma < 0.45555)
             return AVCOL_TRC_GAMMA22;
-        else if (jxl_color->gamma > 2.799 && jxl_color->gamma < 2.801)
+        else if (jxl_color->gamma > 0.35614 && jxl_color->gamma < 0.35814)
             return AVCOL_TRC_GAMMA28;
         else
             av_log(avctx, AV_LOG_WARNING, "Unsupported gamma transfer: %f\n", jxl_color->gamma);