[PATCH 0/1] MR10974: mfreadwrite: Do not return NEED_MORE_INPUT from source_reader_push_transform_samples().

[Conor McCarthy (＠cmccarthy)]

MF_E_TRANSFORM_NEED_MORE_INPUT is only relevant when pulling samples.
Fixes an issue where only one sample can be drained from a decoder in
source_reader_pull_transform_samples() if another transform is present
downstream.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10974

[PATCH 1/1] mfreadwrite: Do not return NEED_MORE_INPUT from source_reader_push_transform_samples().

[Conor McCarthy]

From: Conor McCarthy <[e-mail]>

MF_E_TRANSFORM_NEED_MORE_INPUT is only relevant when pulling samples.
Fixes an issue where only one sample can be drained from a decoder in
source_reader_pull_transform_samples() if another transform is present
downstream.
---
 dlls/mfreadwrite/reader.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/dlls/mfreadwrite/reader.c b/dlls/mfreadwrite/reader.c
index 68b90357928..c9959526b88 100644
--- a/dlls/mfreadwrite/reader.c
+++ b/dlls/mfreadwrite/reader.c
@@ -767,7 +767,10 @@ static HRESULT source_reader_push_transform_samples(struct source_reader *reader
                 && hr != MF_E_TRANSFORM_NEED_MORE_INPUT)
             return hr;
         if (SUCCEEDED(hr = IMFTransform_ProcessInput(entry->transform, 0, sample, 0)))
-            return source_reader_pull_transform_samples(reader, stream, entry);
+        {
+            hr = source_reader_pull_transform_samples(reader, stream, entry);
+            return hr == MF_E_TRANSFORM_NEED_MORE_INPUT ? S_OK : hr;
+        }
     }
     while (hr == MF_E_NOTACCEPTING);
 
@@ -998,8 +1001,7 @@ static HRESULT source_reader_process_sample(struct source_reader *reader, struct
     entry = LIST_ENTRY(ptr, struct transform_entry, entry);
 
     /* It's assumed that decoder has 1 input and 1 output, both id's are 0. */
-    if (SUCCEEDED(hr = source_reader_push_transform_samples(reader, stream, entry, sample))
-            || hr == MF_E_TRANSFORM_NEED_MORE_INPUT)
+    if (SUCCEEDED(hr = source_reader_push_transform_samples(reader, stream, entry, sample)))
         hr = stream->requests ? source_reader_request_sample(reader, stream) : S_OK;
     else
         WARN("Transform failed to process output, hr %#lx.\n", hr);
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10974

[Nikolay Sivov (＠nsivov)]

I'm guessing this is difficult to test reliably?

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10974#note_143604

[Conor McCarthy (＠cmccarthy)]

On Mon Jun 29 13:17:30 2026 +0000, Nikolay Sivov wrote:
> I'm guessing this is difficult to test reliably?
> It very much depends on the compressed stream and decoder, yes. It will not happen unless the decoder requests enough input for multiple output samples before it outputs anything.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10974#note_144425

[Nikolay Sivov (＠nsivov)]

It's difficult for me to tell what's happening, without digging back into it. I'll trust this was tested, and we'll watch out for possible regressions.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10974#note_148237

[PATCH 0/1] MR10974: mfreadwrite: Do not return NEED_MORE_INPUT from source_reader_push_transform_samples(). - approved

[Nikolay Sivov (＠nsivov)]

This merge request was approved by Nikolay Sivov.
-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10974