[FFmpeg-cvslog] avcodec/mjpegenc: Reconstify mjpeg encoder

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Mon Mar 10 04:02:06 2025 +0100| [958c46800e68809bd47d9bff5d55c99ed943ca41] | committer: Andreas Rheinhardt

avcodec/mjpegenc: Reconstify mjpeg encoder

It has been deconstified in 2c2dfd914902d0b41b4bd30d4b19ae08af1d7bc1
because the FFCodec is touched in av_codec_init_static because
of its get_supported_config callback. Yet this is easily remedied:
Only call get_supported_config to set pix_fmts if the codec does
not already have it set.

This also fixes a mismatch between the declaration of ff_mjpeg_encoder
in allcodecs.c and the definition in mjpegenc.c. Said mismatch is
actually undefined behaviour.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=958c46800e68809bd47d9bff5d55c99ed943ca41
---

 libavcodec/allcodecs.c | 9 +++++----
 libavcodec/mjpegenc.c  | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 9820455b38..f10519617e 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -937,10 +937,11 @@ static void av_codec_init_static(void)
 FF_DISABLE_DEPRECATION_WARNINGS
         switch (codec->p.type) {
         case AVMEDIA_TYPE_VIDEO:
-            codec->get_supported_config(NULL, &codec->p,
-                                        AV_CODEC_CONFIG_PIX_FORMAT, 0,
-                                        (const void **) &codec->p.pix_fmts,
-                                        &dummy);
+            if (!codec->p.pix_fmts)
+                codec->get_supported_config(NULL, &codec->p,
+                                            AV_CODEC_CONFIG_PIX_FORMAT, 0,
+                                            (const void **) &codec->p.pix_fmts,
+                                            &dummy);
             break;
         case AVMEDIA_TYPE_AUDIO:
             codec->get_supported_config(NULL, &codec->p,
diff --git a/libavcodec/mjpegenc.c b/libavcodec/mjpegenc.c
index 3ac1010e4f..30f2c9900d 100644
--- a/libavcodec/mjpegenc.c
+++ b/libavcodec/mjpegenc.c
@@ -675,7 +675,7 @@ static int mjpeg_get_supported_config(const AVCodecContext *avctx,
     return ff_default_get_supported_config(avctx, codec, config, flags, out, out_num);
 }
 
-FFCodec ff_mjpeg_encoder = {
+const FFCodec ff_mjpeg_encoder = {
     .p.name         = "mjpeg",
     CODEC_LONG_NAME("MJPEG (Motion JPEG)"),
     .p.type         = AVMEDIA_TYPE_VIDEO,