[FFmpeg-devel] [PATCH 2/2] avcodec/libjxl: use RGB32F or RGBA32F for 32-bit float JPEG XL

[Leo Izen]

Use AV_PIX_FMT_RGB32F or AV_PIX_FMT_RGBA32F for encoding and decoding
JPEG XL files when encountered, rather than returning an error and
refusing to do anything.

Signed-off-by: Leo Izen <leo.izen at gmail.com>
---
 libavcodec/libjxldec.c | 15 +++++++++------
 libavcodec/libjxlenc.c |  1 +
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/libavcodec/libjxldec.c b/libavcodec/libjxldec.c
index de48bea4b2..92b98388d4 100644
--- a/libavcodec/libjxldec.c
+++ b/libavcodec/libjxldec.c
@@ -104,9 +104,12 @@ static enum AVPixelFormat libjxl_get_pix_fmt(void *avctx, const JxlBasicInfo *ba
             return basic_info->alpha_bits ? AV_PIX_FMT_YA8 : AV_PIX_FMT_GRAY8;
         }
         if (basic_info->exponent_bits_per_sample || basic_info->bits_per_sample > 16) {
-            if (basic_info->alpha_bits)
-                return AV_PIX_FMT_NONE;
             format->data_type = JXL_TYPE_FLOAT;
+            if (basic_info->alpha_bits) {
+                av_log(avctx, AV_LOG_WARNING, "Decoding gray+alpha JXL input as RGBA\n");
+                format->num_channels = 4;
+                return AV_PIX_FMT_RGBAF32;
+            }
             return AV_PIX_FMT_GRAYF32;
         }
         format->data_type = JXL_TYPE_UINT16;
@@ -119,10 +122,10 @@ static enum AVPixelFormat libjxl_get_pix_fmt(void *avctx, const JxlBasicInfo *ba
             format->data_type = JXL_TYPE_UINT8;
             return basic_info->alpha_bits ? AV_PIX_FMT_RGBA : AV_PIX_FMT_RGB24;
         }
-        if (basic_info->bits_per_sample > 16)
-            av_log(avctx, AV_LOG_WARNING, "Downsampling larger integer to 16-bit via libjxl\n");
-        if (basic_info->exponent_bits_per_sample)
-            av_log(avctx, AV_LOG_WARNING, "Downsampling float to 16-bit integer via libjxl\n");
+        if (basic_info->exponent_bits_per_sample || basic_info->bits_per_sample > 16) {
+            format->data_type = JXL_TYPE_FLOAT;
+            return basic_info->alpha_bits ? AV_PIX_FMT_RGBAF32 : AV_PIX_FMT_RGBF32;
+        }
         format->data_type = JXL_TYPE_UINT16;
         return basic_info->alpha_bits ? AV_PIX_FMT_RGBA64 : AV_PIX_FMT_RGB48;
     }
diff --git a/libavcodec/libjxlenc.c b/libavcodec/libjxlenc.c
index 0793ed251b..f9ae086e38 100644
--- a/libavcodec/libjxlenc.c
+++ b/libavcodec/libjxlenc.c
@@ -474,6 +474,7 @@ const FFCodec ff_libjxl_encoder = {
     .p.pix_fmts       = (const enum AVPixelFormat[]) {
         AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
         AV_PIX_FMT_RGB48, AV_PIX_FMT_RGBA64,
+        AV_PIX_FMT_RGBF32, AV_PIX_FMT_RGBAF32,
         AV_PIX_FMT_GRAY8, AV_PIX_FMT_YA8,
         AV_PIX_FMT_GRAY16, AV_PIX_FMT_YA16,
         AV_PIX_FMT_GRAYF32,
-- 
2.37.3