From 652d8c083ca5153298f08fc4bdf5e7c13f548e36 Mon Sep 17 00:00:00 2001
From: Steve Lhomme <robux4@ycbcr.xyz>
Date: Wed, 15 Mar 2023 08:24:52 +0100
Subject: [PATCH] vpx: allow decoding of the alpha channel bitstream

libavcodec is enable to do it without VPX.  And when it does, it uses libvpx.
So we can just use libvpx directly.
---
 modules/codec/vpx.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/modules/codec/vpx.c b/modules/codec/vpx.c
index acbac212e6..55ed75171d 100644
--- a/modules/codec/vpx.c
+++ b/modules/codec/vpx.c
@@ -309,14 +309,22 @@ static int OpenDecoder(vlc_object_t *p_this)
     switch (dec->fmt_in->i_codec)
     {
 #ifdef ENABLE_VP8_DECODER
-    case VLC_CODEC_WEBP:
     case VLC_CODEC_VP8:
+        if (dec->fmt_in->i_level) // contains alpha extradata
+            return VLC_ENOTSUP;
+        // fallthrough
+    case VLC_CODEC_WEBP:
+    case VLC_CODEC_VP8ALPHA_ES:
         iface = &vpx_codec_vp8_dx_algo;
         vp_version = 8;
         break;
 #endif
 #ifdef ENABLE_VP9_DECODER
     case VLC_CODEC_VP9:
+        if (dec->fmt_in->i_level) // contains alpha extradata
+            return VLC_ENOTSUP;
+        // fallthrough
+    case VLC_CODEC_VP9ALPHA_ES:
         iface = &vpx_codec_vp9_dx_algo;
         vp_version = 9;
         break;
@@ -404,14 +412,19 @@ static int OpenEncoder(vlc_object_t *p_this)
     switch (p_enc->fmt_out.i_codec)
     {
 #ifdef ENABLE_VP8_ENCODER
-    case VLC_CODEC_WEBP:
     case VLC_CODEC_VP8:
+        if (p_enc->fmt_out.i_level) // contains alpha extradata
+            return VLC_ENOTSUP;
+        // fallthrough
+    case VLC_CODEC_WEBP:
         iface = &vpx_codec_vp8_cx_algo;
         vp_version = 8;
         break;
 #endif
 #ifdef ENABLE_VP9_ENCODER
     case VLC_CODEC_VP9:
+        if (p_enc->fmt_out.i_level) // contains alpha extradata
+            return VLC_ENOTSUP;
         iface = &vpx_codec_vp9_cx_algo;
         vp_version = 9;
         break;