What does HRESULT 0x8004022D (VFW_E_DUPLICATE_NAME) mean?

Status / error code:

Category:

Constant name:

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Facility:

Operating System:

Description:

Practical handling of an attempt to add a filter with a duplicate name failed.

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VFW_E_SAMPLE_REJECTED_EOS	VFW_E_TIMEOUT

VFW_E_DUPLICATE_NAME

Meaning and numerical form

VFW_E_DUPLICATE_NAME is HRESULT 2147746349 (0x8004022D; signed -2147220947). AllStat records its meaning as “An attempt to add a filter with a duplicate name failed”. In practical terms, it is returned when a DirectShow graph cannot add a filter under a name already used by another filter when the operation requires an exact unique name.

The severity bit in 0x8004022D is set, so this result is a failure result rather than a success or informational status. Its facility is 4 (FACILITY_ITF) and its low 16-bit code is 557 (0x022D). Those fields classify the value but do not identify the component instance, call, object or input that produced it.

Evidence to collect

A useful diagnostic record for this result includes the native API or interface method, component or CLSID, process and thread IDs, architecture, apartment where relevant, operation correlation ID, elapsed time, input identity, and the first state-changing event before failure. When diagnosing it, preserve IErrorInfo, an inner HRESULT, Win32 status, device event or provider message when available.

Capture 1 for this HRESULT: requested name and existing filter CLSID using it.
Capture 2 for this HRESULT: graph contents before AddFilter.
Capture 3 for this HRESULT: topology generation and modification thread.

Telemetry for this HRESULT should retain types, lengths, hashes, stable opaque identifiers and lifecycle generations while redacting content and credentials. This makes repeated incidents comparable without exposing media content, file paths, device identifiers or credentials.

Where the failure belongs

This result belongs to DirectShow filter-graph processing. DirectShow is a legacy, component-based media pipeline. Graph state, pin transport, negotiated media types, allocators, clocks, samples, renderers and source filters contribute separate contracts to the operation. The decisive condition is this: a DirectShow graph cannot add a filter under a name already used by another filter when the operation requires an exact unique name. Record the first native producer instead of relying only on a framework exception translated several layers later.

Do not infer from this result alone that reinstalling, rebooting or repeating the whole workflow is appropriate. Because it can cross process and language boundaries, its correction depends on the object identity, lifecycle generation, input and state at the first failing call.

Likely causes

Possible cause 1 for this HRESULT: application code reuses a fixed name for multiple filters.
Possible cause 2 for this HRESULT: a prior failed rebuild left the old filter in the graph.
Possible cause 3 for this HRESULT: concurrent graph modification adds the same logical component twice.

Diagnostic sequence

Capture it at the first native return and identify the exact object and method.
Confirm that the observed path matches this condition: a DirectShow graph cannot add a filter under a name already used by another filter when the operation requires an exact unique name.
compare the live state with the method contract before changing configuration.
collect the code-specific evidence listed above and preserve any more specific preceding error.
change one evidence-backed cause at a time, then repeat the smallest operation that can prove the correction.
Add a regression check that distinguishes it from the related outcomes described below.

Correction and retry boundary

Corrective action 1 for this HRESULT: generate or choose unique graph names.
Corrective action 2 for this HRESULT: remove old filters before rebuilding a branch.
Corrective action 3 for this HRESULT: serialize graph modifications.

Retry guidance for this HRESULT. Retry with a unique name or after removing the previous filter; unchanged retry repeats the collision. A retry must avoid this hazard: replay obsolete samples, duplicate graph changes or reuse interfaces from an earlier topology generation. It must also preserve the evidence needed to locate the original producer of it.

Difference from nearby HRESULTs

VFW_S_DUPLICATE_NAME is successful addition under a modified name, while it indicates the requested add operation failed. Keep these outcomes separate in logs, exception mappings, user messages, dashboards and automated retry policy.

Developer and operational guidance

Code handling it should log the failed stage before cleanup, keep ownership and lifecycle transitions explicit, and avoid converting every failure into a generic message. Tests for this HRESULT should cover the primary cause, one adjacent HRESULT and the retry boundary so a future change cannot turn a deterministic contract failure into an uncontrolled loop.

Operational repair for this HRESULT should use supported filter installation, device, graph-building and renderer configuration paths. Avoid unsupported configuration edits or component replacement unless evidence identifies that layer. Retain the original trace and a post-fix trace so the result can be attributed and the change reversed.

Practical scenario

A preview graph rebuild adds a second renderer named Video Renderer without removing the first; generation-based names prevent it. The result scenario narrows the result to a reproducible contract boundary and supplies a concrete before-and-after test.

Official Microsoft references

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