Simplify

src/torchcodec/decoders/_core/VideoDecoder.cpp

@@ -864,12 +864,10 @@ torch::Tensor VideoDecoder::getFramesPlayedInRangeAudio(
   // We should remove it and seek back to the stream's beginning when needed.
   // See test_multiple_calls
   TORCH_CHECK(
-      (streamInfo.lastDecodedAvFramePts == 0 &&
-       streamInfo.lastDecodedAvFrameDuration == 0) ||
-          (streamInfo.lastDecodedAvFramePts +
-               streamInfo.lastDecodedAvFrameDuration <=
-           secondsToClosestPts(startSeconds, streamInfo.timeBase)),
-      "The previous call's stop_seconds is larger than the current calls's start_seconds (roughly)");
+      streamInfo.lastDecodedAvFramePts +
+              streamInfo.lastDecodedAvFrameDuration <=
+          secondsToClosestPts(startSeconds, streamInfo.timeBase),
+      "Audio decoder cannot seek backwards, or start from the last decoded frame.");
 
   setCursorPtsInSeconds(startSeconds);
 

test/decoders/test_ops.py

@@ -782,27 +782,19 @@ def get_reference_frames(start_seconds, stop_seconds):
         )
 
         # but starting immediately on the same frame raises
-        with pytest.raises(
-            RuntimeError,
-            match="The previous call's stop_seconds is larger than the current calls's start_seconds",
-        ):
+        expected_match = "Audio decoder cannot seek backwards"
+        with pytest.raises(RuntimeError, match=expected_match):
             get_frames_by_pts_in_range_audio(
                 decoder, start_seconds=stop_seconds, stop_seconds=6
             )
 
-        with pytest.raises(
-            RuntimeError,
-            match="The previous call's stop_seconds is larger than the current calls's start_seconds",
-        ):
+        with pytest.raises(RuntimeError, match=expected_match):
             get_frames_by_pts_in_range_audio(
                 decoder, start_seconds=stop_seconds + 1e-4, stop_seconds=6
             )
 
         # and seeking backwards doesn't work either
-        with pytest.raises(
-            RuntimeError,
-            match="The previous call's stop_seconds is larger than the current calls's start_seconds",
-        ):
+        with pytest.raises(RuntimeError, match=expected_match):
             frames = get_frames_by_pts_in_range_audio(
                 decoder, start_seconds=0, stop_seconds=2
             )