| Message ID | 20210824195636.1110845-8-nfraprado@collabora.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
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| Related | show |
On Tue, Aug 24, 2021 at 04:56:26PM -0300, Nícolas F. R. A. Prado wrote: > Instead of using bufferCount as the number of V4L2 buffer slots to > reserve in the vimc and uvcvideo pipeline handlers, use a reasonably > high constant: 16. Overallocating isn't a problem as buffer slots are > cheap. Having too few, on the other hand, could degrade performance. It > is expected that this number will be more than enough for most, if not > all, use cases. > > This makes way for removing bufferCount. > > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> > > --- > > Changes in v8: > - New > > src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 5 +++-- > src/libcamera/pipeline/vimc/vimc.cpp | 5 +++-- > 2 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > index 7821cacfa883..c210cf57750f 100644 > --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp > @@ -91,6 +91,8 @@ private: > { > return static_cast<UVCCameraData *>(camera->_d()); > } > + > + static constexpr unsigned int kUVCBufferSlotCount = 16; > }; > > UVCCameraConfiguration::UVCCameraConfiguration(UVCCameraData *data) > @@ -236,9 +238,8 @@ int PipelineHandlerUVC::exportFrameBuffers(Camera *camera, > int PipelineHandlerUVC::start(Camera *camera, [[maybe_unused]] const ControlList *controls) > { > UVCCameraData *data = cameraData(camera); > - unsigned int count = data->stream_.configuration().bufferCount; > > - int ret = data->video_->importBuffers(count); > + int ret = data->video_->importBuffers(kUVCBufferSlotCount); > if (ret < 0) > return ret; > > diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp > index eebdfd1a4c01..d2943f61a745 100644 > --- a/src/libcamera/pipeline/vimc/vimc.cpp > +++ b/src/libcamera/pipeline/vimc/vimc.cpp > @@ -105,6 +105,8 @@ private: > { > return static_cast<VimcCameraData *>(camera->_d()); > } > + > + static constexpr unsigned int kVimcBufferSlotCount = 16; > }; > > namespace { > @@ -331,9 +333,8 @@ int PipelineHandlerVimc::exportFrameBuffers(Camera *camera, > int PipelineHandlerVimc::start(Camera *camera, [[maybe_unused]] const ControlList *controls) > { > VimcCameraData *data = cameraData(camera); > - unsigned int count = data->stream_.configuration().bufferCount; > > - int ret = data->video_->importBuffers(count); > + int ret = data->video_->importBuffers(kVimcBufferSlotCount); > if (ret < 0) > return ret; > > -- > 2.33.0 >
diff --git a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp index 7821cacfa883..c210cf57750f 100644 --- a/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp +++ b/src/libcamera/pipeline/uvcvideo/uvcvideo.cpp @@ -91,6 +91,8 @@ private: { return static_cast<UVCCameraData *>(camera->_d()); } + + static constexpr unsigned int kUVCBufferSlotCount = 16; }; UVCCameraConfiguration::UVCCameraConfiguration(UVCCameraData *data) @@ -236,9 +238,8 @@ int PipelineHandlerUVC::exportFrameBuffers(Camera *camera, int PipelineHandlerUVC::start(Camera *camera, [[maybe_unused]] const ControlList *controls) { UVCCameraData *data = cameraData(camera); - unsigned int count = data->stream_.configuration().bufferCount; - int ret = data->video_->importBuffers(count); + int ret = data->video_->importBuffers(kUVCBufferSlotCount); if (ret < 0) return ret; diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp index eebdfd1a4c01..d2943f61a745 100644 --- a/src/libcamera/pipeline/vimc/vimc.cpp +++ b/src/libcamera/pipeline/vimc/vimc.cpp @@ -105,6 +105,8 @@ private: { return static_cast<VimcCameraData *>(camera->_d()); } + + static constexpr unsigned int kVimcBufferSlotCount = 16; }; namespace { @@ -331,9 +333,8 @@ int PipelineHandlerVimc::exportFrameBuffers(Camera *camera, int PipelineHandlerVimc::start(Camera *camera, [[maybe_unused]] const ControlList *controls) { VimcCameraData *data = cameraData(camera); - unsigned int count = data->stream_.configuration().bufferCount; - int ret = data->video_->importBuffers(count); + int ret = data->video_->importBuffers(kVimcBufferSlotCount); if (ret < 0) return ret;
Instead of using bufferCount as the number of V4L2 buffer slots to reserve in the vimc and uvcvideo pipeline handlers, use a reasonably high constant: 16. Overallocating isn't a problem as buffer slots are cheap. Having too few, on the other hand, could degrade performance. It is expected that this number will be more than enough for most, if not all, use cases. This makes way for removing bufferCount. Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> --- Changes in v8: - New src/libcamera/pipeline/uvcvideo/uvcvideo.cpp | 5 +++-- src/libcamera/pipeline/vimc/vimc.cpp | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-)