PR #21002 opened by Thomas Gritzan (Phygon) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21002 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21002.patch
Playback to a decklink device with a newer version of the DeckLink SDK (14.3) stalls because the driver code calls IDeckLinkVideoFrame::QueryInterface, which is not implemented by ffmpeg. This patch implements decklink_frame::QueryInterface, so that playback works with both older (12.x) and newer (>= 14.3) drivers. Note: The patch still does not allow the code to compile with DeckLink SDK 14.3 or newer, as the API has changed. >From 22f08f1d0158d5064fa121d03b8330aa29ae8e28 Mon Sep 17 00:00:00 2001 From: Thomas Gritzan <[email protected]> Date: Mon, 24 Nov 2025 00:26:33 +0100 Subject: [PATCH] libavdevice/decklink: Implement QueryInterface to support newer driver Playback to a decklink device with a newer version of the DeckLink SDK (14.3) stalls because the driver code calls IDeckLinkVideoFrame::QueryInterface, which is not implemented by ffmpeg. This patch implements decklink_frame::QueryInterface, so that playback works with both older (12.x) and newer (>= 14.3) drivers. Note: The patch still does not allow the code to compile with DeckLink SDK 14.3 or newer, as the API has changed. --- libavdevice/decklink_enc.cpp | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/libavdevice/decklink_enc.cpp b/libavdevice/decklink_enc.cpp index cb8f91730e..0e743348c6 100644 --- a/libavdevice/decklink_enc.cpp +++ b/libavdevice/decklink_enc.cpp @@ -47,6 +47,11 @@ extern "C" { #include "libklvanc/pixels.h" #endif +static bool IsEqualGUID(const REFIID &iid1, const REFIID &iid2) +{ + return memcmp(&iid1, &iid2, sizeof(REFIID)) == 0; +} + /* DeckLink callback class declaration */ class decklink_frame : public IDeckLinkVideoFrame { @@ -111,7 +116,19 @@ public: _ancillary->AddRef(); return S_OK; } - virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) { return E_NOINTERFACE; } + virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) + { + if (IsEqualGUID(iid, IID_IUnknown) || IsEqualGUID(iid, IID_IDeckLinkVideoFrame)) { + *ppv = static_cast<IDeckLinkVideoFrame*>(this); + } else { + *ppv = NULL; + return E_NOINTERFACE; + } + + AddRef(); + return S_OK; + } + virtual ULONG STDMETHODCALLTYPE AddRef(void) { return ++_refs; } virtual ULONG STDMETHODCALLTYPE Release(void) { -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
