Fix Depacketizer: 1st capt_ts in middle of frame

roc-streaming · Nov 19, 2023 · 55821da · 55821da
1 parent 85509ca
commit 55821da
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Showing 2 changed files with 20 additions and 4 deletions.
diff --git a/src/internal_modules/roc_audio/depacketizer.cpp b/src/internal_modules/roc_audio/depacketizer.cpp
@@ -117,9 +117,17 @@ Depacketizer::read_samples_(sample_t* buff_ptr, sample_t* buff_end, FrameInfo& i
 
             buff_ptr = read_missing_samples_(buff_ptr, buff_ptr + n_samples);
 
+            //           next_capture_ts_
+            //           next_timestamp
+            //                  ↓
+            // Packet           |-----------------|
+            //           timestamp_
+            //               ↓
+            // Frame      |----------------|
+            info.n_filled_samples += n_samples;
             if (!info.capture_ts && valid_capture_ts_) {
-                info.capture_ts =
-                    next_capture_ts_ - sample_spec_.samples_overall_2_ns(mis_samples);
+                info.capture_ts = next_capture_ts_
+                    - sample_spec_.samples_overall_2_ns(info.n_filled_samples);
             }
         }
 
@@ -129,12 +137,14 @@ Depacketizer::read_samples_(sample_t* buff_ptr, sample_t* buff_end, FrameInfo& i
 
             info.n_decoded_samples += n_samples;
             if (n_samples && !info.capture_ts && valid_capture_ts_) {
-                info.capture_ts = next_capture_ts_;
+                info.capture_ts = next_capture_ts_
+                    - sample_spec_.samples_overall_2_ns(info.n_filled_samples);
             }
             if (valid_capture_ts_) {
                 next_capture_ts_ += sample_spec_.samples_overall_2_ns(n_samples);
             }
 
+            info.n_filled_samples += n_samples;
             buff_ptr = new_buff_ptr;
         }
 
@@ -143,12 +153,14 @@ Depacketizer::read_samples_(sample_t* buff_ptr, sample_t* buff_end, FrameInfo& i
         const size_t n_samples = size_t(buff_end - buff_ptr);
 
         if (!info.capture_ts && valid_capture_ts_) {
-            info.capture_ts = next_capture_ts_;
+            info.capture_ts = next_capture_ts_
+                - sample_spec_.samples_overall_2_ns(info.n_filled_samples);
         }
         if (valid_capture_ts_) {
             next_capture_ts_ += sample_spec_.samples_overall_2_ns(n_samples);
         }
 
+        info.n_filled_samples += n_samples;
         return read_missing_samples_(buff_ptr, buff_end);
     }
 }

diff --git a/src/internal_modules/roc_audio/depacketizer.h b/src/internal_modules/roc_audio/depacketizer.h
@@ -60,6 +60,9 @@ class Depacketizer : public IFrameReader, public core::NonCopyable<> {
         // Number of samples decoded from packets into the frame.
         size_t n_decoded_samples;
 
+        // Number of samples filled out in the frame.
+        size_t n_filled_samples;
+
         // Number of packets dropped during frame construction.
         size_t n_dropped_packets;
 
@@ -68,6 +71,7 @@ class Depacketizer : public IFrameReader, public core::NonCopyable<> {
 
         FrameInfo()
             : n_decoded_samples(0)
+            , n_filled_samples(0)
             , n_dropped_packets(0)
             , capture_ts(0) {
         }