C2SoftAvcDec: Fix interlaced input handling

C2 plugin for avc decoder is now updated to appropriately
handle both types of interlaced content, i.e. sent as one
field per one input buffer and sent as two fields per one
input

- Allow bytes consumed to be returned as zero to handle dangling fields
- Do not ignore trailing bytes after decode call as that data may
  contain next field
- Ensure input buffer contains at least 4 bytes
- After signalling new output delay, do not feed the input again

Bug: 135146280
Bug: 152087140
Test: poc in bugs
Test: atest android.media.cts.DecoderTest

Change-Id: I1f6a12878eeebb604a16f8e9edcdf3d631ef5afc
Merged-In: I1f6a12878eeebb604a16f8e9edcdf3d631ef5afc

media/codec2/components/avc/C2SoftAvcDec.cpp

@@ -35,6 +35,7 @@ constexpr size_t kMinInputBufferSize = 2 * 1024 * 1024;
 constexpr char COMPONENT_NAME[] = "c2.android.avc.decoder";
 constexpr uint32_t kDefaultOutputDelay = 8;
 constexpr uint32_t kMaxOutputDelay = 16;
+constexpr uint32_t kMinInputBytes = 4;
 }  // namespace
 
 class C2SoftAvcDec::IntfImpl : public SimpleInterface<void>::BaseParams {
@@ -817,7 +818,7 @@ void C2SoftAvcDec::process(
           inSize, (int)work->input.ordinal.timestamp.peeku(),
           (int)work->input.ordinal.frameIndex.peeku(), work->input.flags);
     size_t inPos = 0;
-    while (inPos < inSize) {
+    while (inPos < inSize && inSize - inPos >= kMinInputBytes) {
         if (C2_OK != ensureDecoderState(pool)) {
             mSignalledError = true;
             work->workletsProcessed = 1u;
@@ -904,7 +905,6 @@ void C2SoftAvcDec::process(
                 work->result = C2_CORRUPTED;
                 return;
             }
-            continue;
         }
         if (0 < s_decode_op.u4_pic_wd && 0 < s_decode_op.u4_pic_ht) {
             if (mHeaderDecoded == false) {
@@ -937,16 +937,7 @@ void C2SoftAvcDec::process(
         if (s_decode_op.u4_output_present) {
             finishWork(s_decode_op.u4_ts, work);
         }
-        if (0 == s_decode_op.u4_num_bytes_consumed) {
-            ALOGD("Bytes consumed is zero. Ignoring remaining bytes");
-            break;
-        }
         inPos += s_decode_op.u4_num_bytes_consumed;
-        if (hasPicture && (inSize - inPos)) {
-            ALOGD("decoded frame in current access nal, ignoring further trailing bytes %d",
-                  (int)inSize - (int)inPos);
-            break;
-        }
     }
     if (eos) {
         drainInternal(DRAIN_COMPONENT_WITH_EOS, pool, work);