[vlc-devel] [PATCH 2/2] dav1d: parse the extra data to get the output chroma

[Steve Lhomme]

If there are some extra data the chroma should be constant and we can estimate
it so that we create the decoder with the proper chroma.
---
 modules/codec/Makefile.am |  3 ++-
 modules/codec/dav1d.c     | 51 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/modules/codec/Makefile.am b/modules/codec/Makefile.am
index 0aede611336..acb5071f569 100644
--- a/modules/codec/Makefile.am
+++ b/modules/codec/Makefile.am
@@ -552,7 +552,8 @@ libtwolame_plugin_la_LIBADD = $(TWOLAME_LIBS) $(LIBM)
 EXTRA_LTLIBRARIES += libtwolame_plugin.la
 codec_LTLIBRARIES += $(LTLIBtwolame)
 
-libdav1d_plugin_la_SOURCES = codec/dav1d.c
+libdav1d_plugin_la_SOURCES = codec/dav1d.c \
+	packetizer/av1_obu.c packetizer/av1_obu.h
 libdav1d_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) $(DAV1D_CFLAGS)
 libdav1d_plugin_la_CFLAGS = $(AM_CFLAGS)
 libdav1d_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(codecdir)'
diff --git a/modules/codec/dav1d.c b/modules/codec/dav1d.c
index 92f6f441464..9ee03f70c86 100644
--- a/modules/codec/dav1d.c
+++ b/modules/codec/dav1d.c
@@ -38,6 +38,7 @@
 #include <dav1d/dav1d.h>
 
 #include "../packetizer/iso_color_tables.h"
+#include "../packetizer/av1_obu.h"
 #include "cc.h"
 
 /****************************************************************************
@@ -391,6 +392,13 @@ static int OpenDecoder(vlc_object_t *p_this)
     p_sys->s.allocator.alloc_picture_callback = NewPicture;
     p_sys->s.allocator.release_picture_callback = FreePicture;
 
+    av1_OBU_sequence_header_t *sequence_hdr = NULL;
+    if (dec->fmt_in.i_extra > 4)
+    {
+        sequence_hdr = AV1_OBU_parse_sequence_header(((uint8_t*)dec->fmt_in.p_extra) + 4,
+                                                        dec->fmt_in.i_extra - 4);
+    }
+
     if (dav1d_open(&p_sys->c, &p_sys->s) < 0)
     {
         msg_Err(p_this, "Could not open the Dav1d decoder");
@@ -406,7 +414,48 @@ static int OpenDecoder(vlc_object_t *p_this)
 
     dec->fmt_out.video.i_width = dec->fmt_in.video.i_width;
     dec->fmt_out.video.i_height = dec->fmt_in.video.i_height;
-    dec->fmt_out.i_codec = VLC_CODEC_I420;
+    if (!sequence_hdr)
+        dec->fmt_out.i_codec = VLC_CODEC_I420;
+    else
+    {
+        // use the sequence header to get a better chroma to start with
+        switch (AV1_get_chroma(sequence_hdr))
+        {
+            case VLC_CODEC_GREY:
+                switch (AV1_get_bitdepth(sequence_hdr))
+                {
+                    case 0: dec->fmt_out.i_codec = VLC_CODEC_GREY; break;
+                    case 1: dec->fmt_out.i_codec = VLC_CODEC_GREY_10L; break;
+                    case 2: dec->fmt_out.i_codec = VLC_CODEC_GREY_12L; break;
+                }
+                break;
+            case VLC_CODEC_I420:
+                switch (AV1_get_bitdepth(sequence_hdr))
+                {
+                    case 0: dec->fmt_out.i_codec = VLC_CODEC_I420; break;
+                    case 1: dec->fmt_out.i_codec = VLC_CODEC_I420_10L; break;
+                    case 2: dec->fmt_out.i_codec = VLC_CODEC_I420_12L; break;
+                }
+                break;
+            case VLC_CODEC_I422:
+                switch (AV1_get_bitdepth(sequence_hdr))
+                {
+                    case 0: dec->fmt_out.i_codec = VLC_CODEC_I422; break;
+                    case 1: dec->fmt_out.i_codec = VLC_CODEC_I422_10L; break;
+                    case 2: dec->fmt_out.i_codec = VLC_CODEC_I422_12L; break;
+                }
+                break;
+            case VLC_CODEC_I444:
+                switch (AV1_get_bitdepth(sequence_hdr))
+                {
+                    case 0: dec->fmt_out.i_codec = VLC_CODEC_I444; break;
+                    case 1: dec->fmt_out.i_codec = VLC_CODEC_I444_10L; break;
+                    case 2: dec->fmt_out.i_codec = VLC_CODEC_I444_12L; break;
+                }
+                break;
+        }
+        AV1_release_sequence_header(sequence_hdr);
+    }
     dec->p_sys = p_sys;
 
     if (dec->fmt_in.video.i_sar_num > 0 && dec->fmt_in.video.i_sar_den > 0) {
-- 
2.26.2