From bab0f7df5672524d403ca300d8d6b9f1bf218fd7 Mon Sep 17 00:00:00 2001 From: David Plowman Date: Wed, 1 Dec 2021 10:15:07 +0000 Subject: pipeline: raspberrypi: Fix under-allocation of embedded data buffers The code was reducing the number of raw stream buffers allocated when the application is providing some of its own. However, it was not taking account of the fact that the application cannot supply embedded data buffers, so it must always allocate a reasonable minimum number of these buffers (possibly more than the number of raw stream buffers) to prevent frame drops. Signed-off-by: David Plowman Reviewed-by: Kieran Bingham Reviewed-by: Naushir Patuck Signed-off-by: Kieran Bingham --- src/libcamera/pipeline/raspberrypi/raspberrypi.cpp | 25 ++++++++++++++-------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'src') diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp index e31fa3b2..045725dd 100644 --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp @@ -1248,18 +1248,25 @@ int PipelineHandlerRPi::prepareBuffers(Camera *camera) /* Decide how many internal buffers to allocate. */ for (auto const stream : data->streams_) { 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. + */ + constexpr unsigned int minBuffers = 4; + if (stream == &data->unicam_[Unicam::Image]) { /* - * 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. + * 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 if (stream == &data->unicam_[Unicam::Embedded]) { + /* + * Embedded data buffers are (currently) for internal use, + * so allocate the minimum required to avoid frame drops. + */ + numBuffers = minBuffers; } else { /* * Since the ISP runs synchronous with the IPA and requests, -- cgit v1.2.1