plugins/screencast: Use buffer format and modifier as specified in spa_video_info_raw

It appears like pipewire can ask kwin to allocate a drm buffer even
though m_dmabufParams has been reset. It's underspecified when pipewire
will start requesting new buffers after changing the stream params. So
use the last reported video info to allocate buffers. If even it is wrong,
then it's an issue somewhere in pipewire.

src/plugins/screencast/screencaststream.cpp

@@ -37,35 +37,79 @@
 namespace KWin
 {
 
-static spa_video_format drmFourCCToSpaVideoFormat(quint32 format)
+static const struct
 {
-    switch (format) {
-    case DRM_FORMAT_ARGB8888:
-        return SPA_VIDEO_FORMAT_BGRA;
-    case DRM_FORMAT_XRGB8888:
-        return SPA_VIDEO_FORMAT_BGRx;
-    case DRM_FORMAT_RGBA8888:
-        return SPA_VIDEO_FORMAT_ABGR;
-    case DRM_FORMAT_RGBX8888:
-        return SPA_VIDEO_FORMAT_xBGR;
-    case DRM_FORMAT_ABGR8888:
-        return SPA_VIDEO_FORMAT_RGBA;
-    case DRM_FORMAT_XBGR8888:
-        return SPA_VIDEO_FORMAT_RGBx;
-    case DRM_FORMAT_BGRA8888:
-        return SPA_VIDEO_FORMAT_ARGB;
-    case DRM_FORMAT_BGRX8888:
-        return SPA_VIDEO_FORMAT_xRGB;
-    case DRM_FORMAT_NV12:
-        return SPA_VIDEO_FORMAT_NV12;
-    case DRM_FORMAT_RGB888:
-        return SPA_VIDEO_FORMAT_BGR;
-    case DRM_FORMAT_BGR888:
-        return SPA_VIDEO_FORMAT_RGB;
-    default:
-        qCDebug(KWIN_SCREENCAST) << "unknown format" << format;
-        return SPA_VIDEO_FORMAT_xRGB;
+    uint32_t drmFormat;
+    spa_video_format spaFormat;
+} supportedFormats[] = {
+    {
+        .drmFormat = DRM_FORMAT_ARGB8888,
+        .spaFormat = SPA_VIDEO_FORMAT_BGRA,
+    },
+    {
+        .drmFormat = DRM_FORMAT_XRGB8888,
+        .spaFormat = SPA_VIDEO_FORMAT_BGRx,
+    },
+    {
+        .drmFormat = DRM_FORMAT_RGBA8888,
+        .spaFormat = SPA_VIDEO_FORMAT_ABGR,
+    },
+    {
+        .drmFormat = DRM_FORMAT_RGBX8888,
+        .spaFormat = SPA_VIDEO_FORMAT_xBGR,
+    },
+    {
+        .drmFormat = DRM_FORMAT_ABGR8888,
+        .spaFormat = SPA_VIDEO_FORMAT_RGBA,
+    },
+    {
+        .drmFormat = DRM_FORMAT_XBGR8888,
+        .spaFormat = SPA_VIDEO_FORMAT_RGBx,
+    },
+    {
+        .drmFormat = DRM_FORMAT_BGRA8888,
+        .spaFormat = SPA_VIDEO_FORMAT_ARGB,
+    },
+    {
+        .drmFormat = DRM_FORMAT_BGRX8888,
+        .spaFormat = SPA_VIDEO_FORMAT_xRGB,
+    },
+    {
+        .drmFormat = DRM_FORMAT_NV12,
+        .spaFormat = SPA_VIDEO_FORMAT_NV12,
+    },
+    {
+        .drmFormat = DRM_FORMAT_RGB888,
+        .spaFormat = SPA_VIDEO_FORMAT_BGR,
+    },
+    {
+        .drmFormat = DRM_FORMAT_BGR888,
+        .spaFormat = SPA_VIDEO_FORMAT_RGB,
+    },
+};
+
+static spa_video_format drmFormatToSpaVideoFormat(quint32 drmFormat)
+{
+    for (const auto &info : supportedFormats) {
+        if (info.drmFormat == drmFormat) {
+            return info.spaFormat;
+        }
     }
+
+    qCDebug(KWIN_SCREENCAST) << "cannot convert drm format to spa format:" << drmFormat;
+    return SPA_VIDEO_FORMAT_UNKNOWN;
+}
+
+static uint32_t spaVideoFormatToDrmFormat(spa_video_format spaFormat)
+{
+    for (const auto &info : supportedFormats) {
+        if (info.spaFormat == spaFormat) {
+            return info.drmFormat;
+        }
+    }
+
+    qCDebug(KWIN_SCREENCAST) << "cannot convert spa format to drm format:" << spaFormat;
+    return DRM_FORMAT_INVALID;
 }
 
 void ScreenCastStream::onStreamStateChanged(pw_stream_state old, pw_stream_state state, const char *error_message)
@@ -214,11 +258,10 @@ void ScreenCastStream::onStreamAddBuffer(pw_buffer *pwBuffer)
 
     struct spa_data *spa_data = pwBuffer->buffer->datas;
     if (spa_data[0].type & (1 << SPA_DATA_DmaBuf)) {
-        Q_ASSERT(m_dmabufParams);
         if (auto dmabuf = DmaBufScreenCastBuffer::create(pwBuffer, GraphicsBufferOptions{
-                                                                       .size = QSize(m_dmabufParams->width, m_dmabufParams->height),
-                                                                       .format = m_dmabufParams->format,
-                                                                       .modifiers = {m_dmabufParams->modifier},
+                                                                       .size = QSize(m_videoFormat.size.width, m_videoFormat.size.height),
+                                                                       .format = spaVideoFormatToDrmFormat(m_videoFormat.format),
+                                                                       .modifiers = {m_videoFormat.modifier},
                                                                    })) {
             pwBuffer->user_data = dmabuf;
             return;
@@ -227,8 +270,8 @@ void ScreenCastStream::onStreamAddBuffer(pw_buffer *pwBuffer)
 
     if (spa_data[0].type & (1 << SPA_DATA_MemFd)) {
         if (auto memfd = MemFdScreenCastBuffer::create(pwBuffer, GraphicsBufferOptions{
-                                                                     .size = m_resolution,
-                                                                     .format = m_drmFormat,
+                                                                     .size = QSize(m_videoFormat.size.width, m_videoFormat.size.height),
+                                                                     .format = spaVideoFormatToDrmFormat(m_videoFormat.format),
                                                                      .software = true,
                                                                  })) {
             pwBuffer->user_data = memfd;
@@ -575,7 +618,7 @@ void ScreenCastStream::invalidateCursor()
 
 QList<const spa_pod *> ScreenCastStream::buildFormats(bool fixate, char buffer[2048])
 {
-    const auto format = drmFourCCToSpaVideoFormat(m_drmFormat);
+    const auto format = drmFormatToSpaVideoFormat(m_drmFormat);
     spa_pod_builder podBuilder = SPA_POD_BUILDER_INIT(buffer, 2048);
     spa_fraction defFramerate = SPA_FRACTION(0, 1);
     spa_fraction minFramerate = SPA_FRACTION(1, 1);