pipewire: read a modifier choice at the right offset - #255
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Picks up celtera/libremidi#255. extract_modifier_choice read a DMA-BUF modifier list at the wrong offset, so a consumer fixated on a modifier the producer never offered and every Vulkan import failed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q
extract_modifier_choice stepped past SPA_POD_CONTENTS(spa_pod_choice, ..) by another sizeof(spa_pod_choice_body). The macro already skips the pod header and the choice body, so it points at the first value; adding the body size again dropped the first two modifiers and read two entries past the end. What a consumer gets back is then a list of neighbouring pod bytes. Fixating on one of those asks the producer to import the dma-buf with a modifier nobody offered, and vkAllocateMemory fails with VK_ERROR_OUT_OF_DEVICE_MEMORY on every frame because the image that layout implies does not fit the buffer. Use SPA_POD_CHOICE_VALUES and SPA_POD_CHOICE_N_VALUES instead, and ignore a choice whose values are not 8 bytes wide, since a modifier is a Long. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q
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Picks up celtera/libremidi#255. extract_modifier_choice read a DMA-BUF modifier list at the wrong offset, so a consumer fixated on a modifier the producer never offered and every Vulkan import failed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q
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Picks up celtera/libremidi#255. extract_modifier_choice read a DMA-BUF modifier list at the wrong offset, so a consumer fixated on a modifier the producer never offered and every Vulkan import failed. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q
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Picks up ossia/libossia#936, which pins celtera/libremidi#255. Without it the DMA-BUF modifier reaching DRMPrimeDecoder is garbage and every Vulkan import fails, so the video input renders black. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q
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extract_modifier_choicestepped pastSPA_POD_CONTENTS(spa_pod_choice, ..)by anothersizeof(spa_pod_choice_body). The macro already skips the pod header and the choice body, so it points at the first value; adding the body size again dropped the first two modifiers and read two entries past the end of the pod.What the consumer gets back is then a list of neighbouring pod bytes. Fixating on one of those asks the producer to import the dma-buf with a modifier nobody offered, and
vkAllocateMemoryfails withVK_ERROR_OUT_OF_DEVICE_MEMORYon every frame, because the image that layout implies does not fit the buffer.This uses
SPA_POD_CHOICE_VALUESandSPA_POD_CHOICE_N_VALUESinstead of stepping the pointer by hand, and ignores a choice whose values are not 8 bytes wide, since a modifier is a Long.Found while debugging ossia score's PipeWire DMA-BUF video input, which rendered black on Vulkan for this reason. With the fix the modifier list parses correctly, the import succeeds and the input renders correct pixels.
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https://claude.ai/code/session_019QWYTEhFJonuUNTEmBfv7Q