more tests

Author: NicolasHug

src/torchcodec/_core/Encoder.cpp

@@ -17,10 +17,19 @@ Encoder::Encoder(
     int sampleRate,
     std::string_view fileName)
     : wf_(wf), sampleRate_(sampleRate) {
+  TORCH_CHECK(
+      wf_.dtype() == torch::kFloat32,
+      "waveform must have float32 dtype, got ",
+      wf_.dtype());
+  TORCH_CHECK(
+      wf_.dim() == 2, "waveform must have 2 dimensions, got ", wf_.dim());
   AVFormatContext* avFormatContext = nullptr;
   avformat_alloc_output_context2(
       &avFormatContext, nullptr, nullptr, fileName.data());
-  TORCH_CHECK(avFormatContext != nullptr, "Couldn't allocate AVFormatContext.");
+  TORCH_CHECK(
+      avFormatContext != nullptr,
+      "Couldn't allocate AVFormatContext. ",
+      "Check the desired extension?");
   avFormatContext_.reset(avFormatContext);
 
   // TODO-ENCODING: Should also support encoding into bytes (use
@@ -51,8 +60,6 @@ Encoder::Encoder(
   // TODO-ENCODING Should also let user choose for compressed formats like mp3.
   avCodecContext_->bit_rate = 0;
 
-  // FFmpeg will raise a reasonably informative error if the desired sample rate
-  // isn't supported by the encoder.
   avCodecContext_->sample_rate = sampleRate_;
 
   // Note: This is the format of the **input** waveform. This doesn't determine

test/decoders/test_ops.py

@@ -1011,6 +1011,37 @@ def decode(self, source) -> torch.Tensor:
         )
         return frames
 
+    def test_bad_input(self, tmp_path):
+
+        valid_output_file = str(tmp_path / ".mp3")
+
+        with pytest.raises(RuntimeError, match="must have float32 dtype, got int"):
+            create_encoder(
+                wf=torch.arange(10, dtype=torch.int),
+                sample_rate=10,
+                filename=valid_output_file,
+            )
+        with pytest.raises(RuntimeError, match="must have 2 dimensions, got 1"):
+            create_encoder(wf=torch.rand(3), sample_rate=10, filename=valid_output_file)
+
+        with pytest.raises(RuntimeError, match="No such file or directory"):
+            create_encoder(
+                wf=torch.rand(10, 10), sample_rate=10, filename="./bad/path.mp3"
+            )
+        with pytest.raises(RuntimeError, match="Check the desired extension"):
+            create_encoder(
+                wf=torch.rand(10, 10), sample_rate=10, filename="./file.bad_extension"
+            )
+
+        # TODO-ENCODING: raise more informative error message when sample rate
+        # isn't supported
+        with pytest.raises(RuntimeError, match="Invalid argument"):
+            create_encoder(
+                wf=self.decode(NASA_AUDIO_MP3),
+                sample_rate=10,
+                filename=valid_output_file,
+            )
+
     def test_round_trip(self, tmp_path):
         # Check that decode(encode(samples)) == samples
         asset = NASA_AUDIO_MP3