Fix bug in old rendering mix presentation finalizer::Finalize()

The loudness info was not being computed correctly for two reason:

1) We need to keep track of a separate bit depth for wav file writing vs loudness calculation
2) We were updating the loudness info iteratively, but this should actually just be done at the end, once all frames have been rendered.

PiperOrigin-RevId: 700011457

iamf/cli/rendering_mix_presentation_finalizer.cc

@@ -680,7 +680,8 @@ absl::Status GenerateRenderingMetadataForLayouts(
     const DecodedUleb128 mix_presentation_id, MixPresentationSubMix& sub_mix,
     int sub_mix_index,
     std::vector<const AudioElementWithData*> audio_elements_in_sub_mix,
-    uint32_t common_sample_rate, uint8_t common_bit_depth,
+    uint32_t common_sample_rate, uint8_t loudness_calculator_bit_depth,
+    uint8_t wav_file_bit_depth,
     std::vector<LayoutRenderingMetadata>& output_layout_rendering_metadata) {
   output_layout_rendering_metadata.resize(sub_mix.layouts.size());
   for (int layout_index = 0; layout_index < sub_mix.layouts.size();
@@ -709,13 +710,13 @@ absl::Status GenerateRenderingMetadataForLayouts(
       // Optionally create a loudness calculator.
       layout_rendering_metadata.loudness_calculator =
           loudness_calculator_factory->CreateLoudnessCalculator(
-              layout, common_sample_rate, common_bit_depth);
+              layout, common_sample_rate, loudness_calculator_bit_depth);
     }
     // Optionally create a wav writer.
-    layout_rendering_metadata.wav_writer =
-        wav_writer_factory(mix_presentation_id, sub_mix_index, layout_index,
-                           layout.loudness_layout, file_path_prefix,
-                           num_channels, common_sample_rate, common_bit_depth);
+    layout_rendering_metadata.wav_writer = wav_writer_factory(
+        mix_presentation_id, sub_mix_index, layout_index,
+        layout.loudness_layout, file_path_prefix, num_channels,
+        common_sample_rate, wav_file_bit_depth);
   }
 
   return absl::OkStatus();
@@ -760,24 +761,29 @@ absl::Status GenerateRenderingMetadataForSubmixes(  // NOLINT
     bool requires_resampling;
     RETURN_IF_NOT_OK(GetCommonSampleRateAndBitDepthFromAudioElementIds(
         audio_elements_in_sub_mix, submix_rendering_metadata.common_sample_rate,
-        submix_rendering_metadata.common_bit_depth, requires_resampling));
+        submix_rendering_metadata.loudness_calculator_bit_depth,
+        requires_resampling));
     if (requires_resampling) {
       // TODO(b/274689885): Convert to a common sample rate and/or bit-depth.
       return absl::UnimplementedError(
           "This implementation does not support mixing different sample rates "
           "or bit-depths.");
     }
-    submix_rendering_metadata.common_bit_depth =
+    // TODO(b/380487606): Add test coverage for the case where we have
+    // differing bit depths for the wav file and loudness calculator.
+    submix_rendering_metadata.wav_file_bit_depth =
         output_wav_file_bit_depth_override.has_value()
             ? *output_wav_file_bit_depth_override
-            : submix_rendering_metadata.common_bit_depth;
+            : submix_rendering_metadata.loudness_calculator_bit_depth;
     std::vector<LayoutRenderingMetadata>& layout_rendering_metadata =
         submix_rendering_metadata.layout_rendering_metadata;
     RETURN_IF_NOT_OK(GenerateRenderingMetadataForLayouts(
         renderer_factory, loudness_calculator_factory, wav_writer_factory,
         file_path_prefix, mix_presentation_id, sub_mix, sub_mix_index,
         audio_elements_in_sub_mix, submix_rendering_metadata.common_sample_rate,
-        submix_rendering_metadata.common_bit_depth, layout_rendering_metadata));
+        submix_rendering_metadata.loudness_calculator_bit_depth,
+        submix_rendering_metadata.wav_file_bit_depth,
+        layout_rendering_metadata));
   }
   return absl::OkStatus();
 }
@@ -855,7 +861,7 @@ absl::Status RenderWriteAndCalculateLoudnessForTemporalUnit(
           submix_rendering_metadata.common_sample_rate, rendered_samples));
       if (layout_rendering_metadata.wav_writer != nullptr) {
         RETURN_IF_NOT_OK(WriteRenderedSamples(
-            rendered_samples, submix_rendering_metadata.common_bit_depth,
+            rendered_samples, submix_rendering_metadata.wav_file_bit_depth,
             *layout_rendering_metadata.wav_writer));
       }
       if (layout_rendering_metadata.loudness_calculator != nullptr) {
@@ -892,7 +898,7 @@ absl::Status RenderWriteAndCalculateLoudnessForTemporalUnit(
       start_timestamp = layout_rendering_metadata.start_timestamp;
       if (layout_rendering_metadata.wav_writer != nullptr) {
         RETURN_IF_NOT_OK(WriteRenderedSamples(
-            rendered_samples, submix_rendering_metadata.common_bit_depth,
+            rendered_samples, submix_rendering_metadata.wav_file_bit_depth,
             *layout_rendering_metadata.wav_writer));
       }
       if (layout_rendering_metadata.loudness_calculator != nullptr) {
@@ -991,9 +997,9 @@ absl::Status RenderingMixPresentationFinalizer::Finalize(
       RETURN_IF_NOT_OK(RenderWriteAndCalculateLoudnessForTemporalUnit(
           id_to_time_to_labeled_frame, parameter_blocks, rendering_metadata,
           overall_start_timestamp));
-      RETURN_IF_NOT_OK(UpdateLoudnessInfo(
-          validate_loudness_, rendering_metadata, mix_presentation_obu));
     }
+    RETURN_IF_NOT_OK(UpdateLoudnessInfo(validate_loudness_, rendering_metadata,
+                                        mix_presentation_obu));
     i++;
   }
 

iamf/cli/rendering_mix_presentation_finalizer.h

@@ -80,7 +80,8 @@ class RenderingMixPresentationFinalizer {
   // and/or calculating loudness based on the rendered output.
   struct SubmixRenderingMetadata {
     uint32_t common_sample_rate;
-    uint8_t common_bit_depth;
+    uint8_t wav_file_bit_depth;
+    uint8_t loudness_calculator_bit_depth;
     std::vector<SubMixAudioElement> audio_elements_in_sub_mix;
     // Mix gain applied to the entire submix.
     MixGainParamDefinition mix_gain;