avcodec: Check against codec format list

There exist few formats (deprecated though) used by mjpeg decoder
and encoder that maps to the same GStreamer format. To properly
pick the right format, also lookup each Codec list before accepting
the format. This fixes error when trying to use mjpeg encoder.

Note that this may results in faded colors. In fact, these special
format are meant to specify that this is full range YUV. Colorimetry
in gst-libav is not yet implemented, hence is ignored in general. So
I think it's fine to first fix the issue before addressing the missing
feature.

https://bugzilla.gnome.org/show_bug.cgi?id=750398

diff --git a/ext/libav/gstavcodecmap.c b/ext/libav/gstavcodecmap.c
index b5ecfb9..81f36fd 100644 (file)
--- a/ext/libav/gstavcodecmap.c
+++ b/ext/libav/gstavcodecmap.c
@@ -2607,17 +2607,36 @@ gst_ffmpeg_pixfmt_to_videoformat (enum PixelFormat pixfmt)
   return GST_VIDEO_FORMAT_UNKNOWN;
 }
 
-enum PixelFormat
-gst_ffmpeg_videoformat_to_pixfmt (GstVideoFormat format)
+static enum PixelFormat
+gst_ffmpeg_videoformat_to_pixfmt_for_codec (GstVideoFormat format,
+    const AVCodec * codec)
 {
   guint i;
 
-  for (i = 0; i < G_N_ELEMENTS (pixtofmttable); i++)
-    if (pixtofmttable[i].format == format)
-      return pixtofmttable[i].pixfmt;
+  for (i = 0; i < G_N_ELEMENTS (pixtofmttable); i++) {
+    if (pixtofmttable[i].format == format) {
+      gint j;
+
+      if (codec && codec->pix_fmts) {
+        for (j = 0; codec->pix_fmts[j] != -1; j++) {
+          if (pixtofmttable[i].pixfmt == codec->pix_fmts[j])
+            return pixtofmttable[i].pixfmt;
+        }
+      } else {
+        return pixtofmttable[i].pixfmt;
+      }
+    }
+  }
+
   return AV_PIX_FMT_NONE;
 }
 
+enum PixelFormat
+gst_ffmpeg_videoformat_to_pixfmt (GstVideoFormat format)
+{
+  return gst_ffmpeg_videoformat_to_pixfmt_for_codec (format, NULL);
+}
+
 void
 gst_ffmpeg_videoinfo_to_context (GstVideoInfo * info, AVCodecContext * context)
 {
@@ -2643,7 +2662,8 @@ gst_ffmpeg_videoinfo_to_context (GstVideoInfo * info, AVCodecContext * context)
   context->sample_aspect_ratio.den = GST_VIDEO_INFO_PAR_D (info);
 
   context->pix_fmt =
-      gst_ffmpeg_videoformat_to_pixfmt (GST_VIDEO_INFO_FORMAT (info));
+      gst_ffmpeg_videoformat_to_pixfmt_for_codec (GST_VIDEO_INFO_FORMAT (info),
+      context->codec);
 }
 
 void