MediaCodec: expose # of input slots in block model

Bug: 159891571
Bug: 363384866
Test: atest CtsMediaV2TestCases:android.mediav2.cts.CodecUnitTest
Change-Id: I2c060a260f2f8553111eaa4193fc0d6a44b7a0e1
diff --git a/media/codec2/sfplugin/CCodecBufferChannel.cpp b/media/codec2/sfplugin/CCodecBufferChannel.cpp
index e2b28dc..d67a876 100644
--- a/media/codec2/sfplugin/CCodecBufferChannel.cpp
+++ b/media/codec2/sfplugin/CCodecBufferChannel.cpp
@@ -1836,6 +1836,9 @@
                     channelCount.value,
                     pcmEncoding ? pcmEncoding.value : C2Config::PCM_16);
         }
+        if (!buffersBoundToCodec) {
+            inputFormat->setInt32(KEY_NUM_SLOTS, numInputSlots);
+        }
         bool conforming = (apiFeatures & API_SAME_INPUT_BUFFER);
         // For encrypted content, framework decrypts source buffer (ashmem) into
         // C2Buffers. Thus non-conforming codecs can process these.
@@ -2356,9 +2359,11 @@
 }
 
 void CCodecBufferChannel::onWorkDone(
-        std::unique_ptr<C2Work> work, const sp<AMessage> &outputFormat,
+        std::unique_ptr<C2Work> work,
+        const sp<AMessage> &inputFormat,
+        const sp<AMessage> &outputFormat,
         const C2StreamInitDataInfo::output *initData) {
-    if (handleWork(std::move(work), outputFormat, initData)) {
+    if (handleWork(std::move(work), inputFormat, outputFormat, initData)) {
         feedInputBufferIfAvailable();
     }
 }
@@ -2388,6 +2393,7 @@
 
 bool CCodecBufferChannel::handleWork(
         std::unique_ptr<C2Work> work,
+        const sp<AMessage> &inputFormat,
         const sp<AMessage> &outputFormat,
         const C2StreamInitDataInfo::output *initData) {
     {
@@ -2561,6 +2567,9 @@
         } else {
             input->numSlots = newNumSlots;
         }
+        if (inputFormat->contains(KEY_NUM_SLOTS)) {
+            inputFormat->setInt32(KEY_NUM_SLOTS, input->numSlots);
+        }
     }
     size_t numOutputSlots = 0;
     uint32_t reorderDepth = 0;