From a3b0aa5511f9e7fe76ec5966a6031d3c9d02a3f2 Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Thu, 18 Nov 2021 16:42:14 +0000 Subject: pipeline: raspberrypi: Rework the internal buffer allocation scheme For simplicity, the pipeline handler currently look at the maximum number of buffers set in the StreamConfiguration by the user and allocate the same number of internal buffers for all device nodes. This would likely overallocate buffers for some nodes. Rework this logic to try and minimise overallcations without compromising performance. The key change is to mostly decouple the number of internal buffers allocated from number of buffers requested by the user through the StreamConfiguration. For ISP nodes, we only ever need 1 set of internal buffers, as the hardware runs synchronous with the requests and IPA. For Unicam nodes, allocate a minimum for 4 buffers (exported + internal), but also require at least 2 internal buffers to minimise frame drops. Signed-off-by: Naushir Patuck Reviewed-by: Kieran Bingham Reviewed-by: Umang Jain Reviewed-by: Laurent Pinchart Signed-off-by: Kieran Bingham --- src/libcamera/pipeline/raspberrypi/raspberrypi.cpp | 43 ++++++++++++++++------ 1 file changed, 32 insertions(+), 11 deletions(-) (limited to 'src/libcamera/pipeline/raspberrypi/raspberrypi.cpp') diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp index 11d3c2b1..4f6c699a 100644 --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp @@ -1211,21 +1211,42 @@ int PipelineHandlerRPi::queueAllBuffers(Camera *camera) int PipelineHandlerRPi::prepareBuffers(Camera *camera) { RPiCameraData *data = cameraData(camera); + unsigned int numRawBuffers = 0; int ret; - /* - * Decide how many internal buffers to allocate. For now, simply look - * at how many external buffers will be provided. We'll need to improve - * this logic. However, we really must have all streams allocate the same - * number of buffers to simplify error handling in queueRequestDevice(). - */ - unsigned int maxBuffers = 0; - for (const Stream *s : camera->streams()) - if (static_cast(s)->isExternal()) - maxBuffers = std::max(maxBuffers, s->configuration().bufferCount); + for (Stream *s : camera->streams()) { + if (isRaw(s->configuration().pixelFormat)) { + numRawBuffers = s->configuration().bufferCount; + break; + } + } + /* Decide how many internal buffers to allocate. */ for (auto const stream : data->streams_) { - ret = stream->prepareBuffers(maxBuffers); + unsigned int numBuffers; + + if (stream == &data->unicam_[Unicam::Image] || + stream == &data->unicam_[Unicam::Embedded]) { + /* + * For Unicam, allocate a minimum of 4 buffers as we want + * to avoid any frame drops. If an application has configured + * a RAW stream, allocate additional buffers to make up the + * minimum, but ensure we have at least 2 sets of internal + * buffers to use to minimise frame drops. + */ + constexpr unsigned int minBuffers = 4; + numBuffers = std::max(2, minBuffers - numRawBuffers); + } else { + /* + * Since the ISP runs synchronous with the IPA and requests, + * we only ever need one set of internal buffers. Any buffers + * the application wants to hold onto will already be exported + * through PipelineHandlerRPi::exportFrameBuffers(). + */ + numBuffers = 1; + } + + ret = stream->prepareBuffers(numBuffers); if (ret < 0) return ret; } -- cgit v1.2.1