[libcamera-devel] [PATCH v6 6/7] android: post_processor: Drop return value for process()

[Umang Jain]

Hi Hiro,

On 10/25/21 5:26 PM, Hirokazu Honda wrote:
> Hi, Umang, thank you for the patch.
>
> On Sat, Oct 23, 2021 at 7:33 PM Umang Jain <umang.jain at ideasonboard.com> wrote:
>> PostProcessor::process() is invoked by CameraStream class
>> in case any post-processing is required for the camera stream.
>> The failure or success is checked via the value returned by
>> CameraStream::process().
>>
>> Now that the post-processor notifies about the post-processing
>> completion operation, we can drop the return value of
>> PostProcessor::process(). The status of post-processing is passed
>> to CameraDevice::streamProcessingComplete() by the
>> PostProcessor::processComplete signal's slot.
>>
>> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>> ---
>>   src/android/camera_stream.cpp            |  4 +++-
>>   src/android/jpeg/post_processor_jpeg.cpp |  6 ++----
>>   src/android/jpeg/post_processor_jpeg.h   |  2 +-
>>   src/android/post_processor.h             |  2 +-
>>   src/android/yuv/post_processor_yuv.cpp   | 10 ++++------
>>   src/android/yuv/post_processor_yuv.h     |  2 +-
>>   6 files changed, 12 insertions(+), 14 deletions(-)
>>
>> diff --git a/src/android/camera_stream.cpp b/src/android/camera_stream.cpp
>> index 4e275cde..45d0607d 100644
>> --- a/src/android/camera_stream.cpp
>> +++ b/src/android/camera_stream.cpp
>> @@ -194,7 +194,9 @@ int CameraStream::process(const FrameBuffer &source,
>>
>>          dest.srcBuffer = &source;
>>
>> -       return postProcessor_->process(&dest);
>> +       postProcessor_->process(&dest);
>> +
>> +       return 0;
>>   }
> Shall we also drop the return value of CameraStream::process() as we
> process any case by streamProcessingComplete()?
> I think whether streamProcessingComplete() is called depends on the
> return value of CameraStream::process(), which may be error-prone?


No, this was discussed before. We want to handle CameraStream::process() 
synchronously, and streamProcessingComplete() will error-handle for the 
async only. This is the design we agreed upon.

>
>>   FrameBuffer *CameraStream::getBuffer()
>> diff --git a/src/android/jpeg/post_processor_jpeg.cpp b/src/android/jpeg/post_processor_jpeg.cpp
>> index cbbe7128..9d7523cb 100644
>> --- a/src/android/jpeg/post_processor_jpeg.cpp
>> +++ b/src/android/jpeg/post_processor_jpeg.cpp
>> @@ -98,7 +98,7 @@ void PostProcessorJpeg::generateThumbnail(const FrameBuffer &source,
>>          }
>>   }
>>
>> -int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
>> +void PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
>>   {
>>          ASSERT(encoder_);
>>
>> @@ -199,7 +199,7 @@ int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuf
>>          if (jpeg_size < 0) {
>>                  LOG(JPEG, Error) << "Failed to encode stream image";
>>                  processComplete.emit(streamBuffer, PostProcessor::Status::Error);
>> -               return jpeg_size;
>> +               return;
>>          }
>>
>>          /* Fill in the JPEG blob header. */
>> @@ -213,6 +213,4 @@ int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuf
>>          /* Update the JPEG result Metadata. */
>>          resultMetadata->addEntry(ANDROID_JPEG_SIZE, jpeg_size);
>>          processComplete.emit(streamBuffer, PostProcessor::Status::Success);
>> -
>> -       return 0;
>>   }
>> diff --git a/src/android/jpeg/post_processor_jpeg.h b/src/android/jpeg/post_processor_jpeg.h
>> index 92385548..43fcbe60 100644
>> --- a/src/android/jpeg/post_processor_jpeg.h
>> +++ b/src/android/jpeg/post_processor_jpeg.h
>> @@ -22,7 +22,7 @@ public:
>>
>>          int configure(const libcamera::StreamConfiguration &incfg,
>>                        const libcamera::StreamConfiguration &outcfg) override;
>> -       int process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) override;
>> +       void process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) override;
>>
>>   private:
>>          void generateThumbnail(const libcamera::FrameBuffer &source,
>> diff --git a/src/android/post_processor.h b/src/android/post_processor.h
>> index 4ac74fcf..5ec71c93 100644
>> --- a/src/android/post_processor.h
>> +++ b/src/android/post_processor.h
>> @@ -27,7 +27,7 @@ public:
>>
>>          virtual int configure(const libcamera::StreamConfiguration &inCfg,
>>                                const libcamera::StreamConfiguration &outCfg) = 0;
>> -       virtual int process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) = 0;
>> +       virtual void process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) = 0;
>>
>>          libcamera::Signal<Camera3RequestDescriptor::StreamBuffer *, Status> processComplete;
>>   };
>> diff --git a/src/android/yuv/post_processor_yuv.cpp b/src/android/yuv/post_processor_yuv.cpp
>> index 8e77bf57..1ac7995a 100644
>> --- a/src/android/yuv/post_processor_yuv.cpp
>> +++ b/src/android/yuv/post_processor_yuv.cpp
>> @@ -49,21 +49,21 @@ int PostProcessorYuv::configure(const StreamConfiguration &inCfg,
>>          return 0;
>>   }
>>
>> -int PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
>> +void PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
>>   {
>>          const FrameBuffer &source = *streamBuffer->srcBuffer;
>>          CameraBuffer *destination = streamBuffer->destBuffer.get();
>>
>>          if (!isValidBuffers(source, *destination)) {
>>                  processComplete.emit(streamBuffer, PostProcessor::Status::Error);
>> -               return -EINVAL;
>> +               return;
>>          }
>>
>>          const MappedFrameBuffer sourceMapped(&source, MappedFrameBuffer::MapFlag::Read);
>>          if (!sourceMapped.isValid()) {
>>                  LOG(YUV, Error) << "Failed to mmap camera frame buffer";
>>                  processComplete.emit(streamBuffer, PostProcessor::Status::Error);
>> -               return -EINVAL;
>> +               return;
>>          }
>>
>>          int ret = libyuv::NV12Scale(sourceMapped.planes()[0].data(),
>> @@ -81,12 +81,10 @@ int PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuff
>>          if (ret) {
>>                  LOG(YUV, Error) << "Failed NV12 scaling: " << ret;
>>                  processComplete.emit(streamBuffer, PostProcessor::Status::Error);
>> -               return -EINVAL;
>> +               return;
>>          }
>>
>>          processComplete.emit(streamBuffer, PostProcessor::Status::Success);
>> -
>> -       return 0;
>>   }
>>
>>   bool PostProcessorYuv::isValidBuffers(const FrameBuffer &source,
>> diff --git a/src/android/yuv/post_processor_yuv.h b/src/android/yuv/post_processor_yuv.h
>> index 5954e11b..39ec7994 100644
>> --- a/src/android/yuv/post_processor_yuv.h
>> +++ b/src/android/yuv/post_processor_yuv.h
>> @@ -18,7 +18,7 @@ public:
>>
>>          int configure(const libcamera::StreamConfiguration &incfg,
>>                        const libcamera::StreamConfiguration &outcfg) override;
>> -       int process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) override;
>> +       void process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) override;
>>
>>   private:
>>          bool isValidBuffers(const libcamera::FrameBuffer &source,
>> --
>> 2.31.1
>>