[PATCH v2 0/1] MR6533: Draft: winegstreamer: Tweak h264 caps conversion.

[Rémi Bernon]

--
  v2: winegstreamer: Pass H264 codec data as streamheader if it's not parsed yet.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6533

[PATCH v2 1/1] winegstreamer: Pass H264 codec data as streamheader if it's not parsed yet.

[Rémi Bernon]

From: Rémi Bernon <rbernon(a)codeweavers.com>

And set stream-format to avc if it is, as h264parse doesn't expect a
codec_data otherwise.

Native demuxers and decoders expect the H264 codec data to be appended
SPS/PPS NALs, but Wine sometimes only gets it in parsed format if it's
stored like that in an avcC MP4 atom.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=57204
---
 dlls/winegstreamer/wg_media_type.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/dlls/winegstreamer/wg_media_type.c b/dlls/winegstreamer/wg_media_type.c
index 300dace5c52..5de8386522d 100644
--- a/dlls/winegstreamer/wg_media_type.c
+++ b/dlls/winegstreamer/wg_media_type.c
@@ -288,14 +288,34 @@ static void init_caps_from_video_cinepak(GstCaps *caps, const MFVIDEOFORMAT *for
     gst_structure_set_name(gst_caps_get_structure(caps, 0), "video/x-cinepak");
 }
 
+static int is_h264_start_code(UINT32 value)
+{
+    return value == 0x10000000 || (value << 8) == 0x10000000;
+}
+
 static void init_caps_from_video_h264(GstCaps *caps, const MFVIDEOFORMAT *format, UINT format_size)
 {
-    init_caps_codec_data(caps, format + 1, format_size - sizeof(*format));
+    GstBuffer *buffer;
 
     gst_structure_remove_field(gst_caps_get_structure(caps, 0), "format");
     gst_structure_set_name(gst_caps_get_structure(caps, 0), "video/x-h264");
-    gst_caps_set_simple(caps, "stream-format", G_TYPE_STRING, "byte-stream", NULL);
     gst_caps_set_simple(caps, "alignment", G_TYPE_STRING, "au", NULL);
+    if (format_size <= sizeof(*format) || !(buffer = gst_buffer_new_and_alloc(format_size - sizeof(*format))))
+        gst_caps_set_simple(caps, "stream-format", G_TYPE_STRING, "byte-stream", NULL);
+    else if (format_size - sizeof(*format) >= 4 && is_h264_start_code( *(UINT32 *)(format + 1) ))
+    {
+        gst_buffer_fill(buffer, 0, format + 1, format_size - sizeof(*format));
+        gst_caps_set_simple(caps, "streamheader", GST_TYPE_BUFFER, buffer, NULL);
+        gst_caps_set_simple(caps, "stream-format", G_TYPE_STRING, "byte-stream", NULL);
+        gst_buffer_unref(buffer);
+    }
+    else
+    {
+        gst_buffer_fill(buffer, 0, format + 1, format_size - sizeof(*format));
+        gst_caps_set_simple(caps, "codec_data", GST_TYPE_BUFFER, buffer, NULL);
+        gst_caps_set_simple(caps, "stream-format", G_TYPE_STRING, "avc", NULL);
+        gst_buffer_unref(buffer);
+    }
 }
 
 static void init_caps_from_video_wmv(GstCaps *caps, const MFVIDEOFORMAT *format, UINT format_size,
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/6533

[PATCH v2 0/1] MR6533: winegstreamer: Tweak h264 caps conversion.

[Rémi Bernon]

v2: Drop the 'au' alignment removal for now as it breaks some tests.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6533#note_82734

[PATCH v2 0/1] MR6533: winegstreamer: Tweak h264 caps conversion.

[Elizabeth Figura (＠zfigura)]

That doesn't look right. The documentation for both the Media Foundation H.264 decoder and for the MPEG-4 file sink states that the stream must be in Annex B format, which is equivalent to stream-format=byte-stream.

Probably what's needed instead is a repeat of !4600.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6533#note_83103

[PATCH v2 0/1] MR6533: winegstreamer: Tweak h264 caps conversion.

[Elizabeth Figura (＠zfigura)]

If it really is possible to pass AVC data to these elements, it needs tests.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6533#note_83105