Handle null return from ToI420 in encoders

In cases where ToI420 fails it should be able to return null.

Bug: webrtc:12877
Change-Id: Ia13859c104d978a29712ae10f8e15acada8406ac
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/222613
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Evan Shrubsole <eshr@google.com>
Cr-Commit-Position: refs/heads/master@{#34342}

modules/video_coding/codecs/av1/libaom_av1_encoder.cc

diff --git a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
index 84f3453..3b5fdd7 100644
--- a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
+++ b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
@@ -588,12 +588,26 @@
     // kNative. As a workaround to this, we perform ToI420() a second time.
     // TODO(https://crbug.com/webrtc/12602): When Android buffers have a correct
     // ToI420() implementaion, remove his workaround.
+    if (!converted_buffer) {
+      RTC_LOG(LS_ERROR) << "Failed to convert "
+                        << VideoFrameBufferTypeToString(
+                               converted_buffer->type())
+                        << " image to I420. Can't encode frame.";
+      return WEBRTC_VIDEO_CODEC_ENCODER_FAILURE;
+    }
     if (converted_buffer->type() != VideoFrameBuffer::Type::kI420 &&
         converted_buffer->type() != VideoFrameBuffer::Type::kI420A) {
       converted_buffer = converted_buffer->ToI420();
       RTC_CHECK(converted_buffer->type() == VideoFrameBuffer::Type::kI420 ||
                 converted_buffer->type() == VideoFrameBuffer::Type::kI420A);
     }
+    if (!converted_buffer) {
+      RTC_LOG(LS_ERROR) << "Failed to convert "
+                        << VideoFrameBufferTypeToString(
+                               converted_buffer->type())
+                        << " image to I420. Can't encode frame.";
+      return WEBRTC_VIDEO_CODEC_ENCODER_FAILURE;
+    }
     prepped_input_frame = VideoFrame(converted_buffer, frame.timestamp(),
                                      frame.render_time_ms(), frame.rotation());
   }

modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc

diff --git a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
index dd72872..e2849db 100644
--- a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
+++ b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
@@ -1336,6 +1336,13 @@
     if (converted_buffer->type() != VideoFrameBuffer::Type::kI420 &&
         converted_buffer->type() != VideoFrameBuffer::Type::kI420A) {
       converted_buffer = converted_buffer->ToI420();
+      if (!converted_buffer) {
+        RTC_LOG(LS_ERROR) << "Failed to convert "
+                          << VideoFrameBufferTypeToString(
+                                 converted_buffer->type())
+                          << " image to I420. Can't encode frame.";
+        return {};
+      }
       RTC_CHECK(converted_buffer->type() == VideoFrameBuffer::Type::kI420 ||
                 converted_buffer->type() == VideoFrameBuffer::Type::kI420A);
     }

modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc

diff --git a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
index 2a7b125..511e6df 100644
--- a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
+++ b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
@@ -1068,8 +1068,15 @@
           break;
         }
         default: {
-          i010_copy =
-              I010Buffer::Copy(*input_image.video_frame_buffer()->ToI420());
+          auto i420_buffer = input_image.video_frame_buffer()->ToI420();
+          if (!i420_buffer) {
+            RTC_LOG(LS_ERROR) << "Failed to convert "
+                              << VideoFrameBufferTypeToString(
+                                     input_image.video_frame_buffer()->type())
+                              << " image to I420. Can't encode frame.";
+            return WEBRTC_VIDEO_CODEC_ERROR;
+          }
+          i010_copy = I010Buffer::Copy(*i420_buffer);
           i010_buffer = i010_copy.get();
         }
       }
@@ -1908,6 +1915,12 @@
     if (converted_buffer->type() != VideoFrameBuffer::Type::kI420 &&
         converted_buffer->type() != VideoFrameBuffer::Type::kI420A) {
       converted_buffer = converted_buffer->ToI420();
+      if (!converted_buffer) {
+        RTC_LOG(LS_ERROR) << "Failed to convert "
+                          << VideoFrameBufferTypeToString(buffer->type())
+                          << " image to I420. Can't encode frame.";
+        return {};
+      }
       RTC_CHECK(converted_buffer->type() == VideoFrameBuffer::Type::kI420 ||
                 converted_buffer->type() == VideoFrameBuffer::Type::kI420A);
     }