Remove streamIndex parameter from core and ops APIs (#509)

Author: NicolasHug

src/torchcodec/_samplers/video_clip_sampler.py

@@ -242,7 +242,6 @@ def _get_clips_for_index_based_sampling(
             ]
             frames, *_ = get_frames_at_indices(
                 video_decoder,
-                stream_index=metadata_json["bestVideoStreamIndex"],
                 frame_indices=batch_indexes,
             )
             clips.append(frames)

src/torchcodec/decoders/_core/VideoDecoderOps.cpp

@@ -39,24 +39,23 @@ TORCH_LIBRARY(torchcodec_ns, m) {
   m.def(
       "get_frame_at_pts(Tensor(a!) decoder, float seconds) -> (Tensor, Tensor, Tensor)");
   m.def(
-      "get_frame_at_index(Tensor(a!) decoder, *, int stream_index, int frame_index) -> (Tensor, Tensor, Tensor)");
+      "get_frame_at_index(Tensor(a!) decoder, *, int frame_index) -> (Tensor, Tensor, Tensor)");
   m.def(
-      "get_frames_at_indices(Tensor(a!) decoder, *, int stream_index, int[] frame_indices) -> (Tensor, Tensor, Tensor)");
+      "get_frames_at_indices(Tensor(a!) decoder, *, int[] frame_indices) -> (Tensor, Tensor, Tensor)");
   m.def(
-      "get_frames_in_range(Tensor(a!) decoder, *, int stream_index, int start, int stop, int? step=None) -> (Tensor, Tensor, Tensor)");
+      "get_frames_in_range(Tensor(a!) decoder, *, int start, int stop, int? step=None) -> (Tensor, Tensor, Tensor)");
   m.def(
-      "get_frames_by_pts_in_range(Tensor(a!) decoder, *, int stream_index, float start_seconds, float stop_seconds) -> (Tensor, Tensor, Tensor)");
+      "get_frames_by_pts_in_range(Tensor(a!) decoder, *, float start_seconds, float stop_seconds) -> (Tensor, Tensor, Tensor)");
   m.def(
-      "get_frames_by_pts(Tensor(a!) decoder, *, int stream_index, float[] timestamps) -> (Tensor, Tensor, Tensor)");
-  m.def(
-      "_get_key_frame_indices(Tensor(a!) decoder, int stream_index) -> Tensor");
+      "get_frames_by_pts(Tensor(a!) decoder, *, float[] timestamps) -> (Tensor, Tensor, Tensor)");
+  m.def("_get_key_frame_indices(Tensor(a!) decoder) -> Tensor");
   m.def("get_json_metadata(Tensor(a!) decoder) -> str");
   m.def("get_container_json_metadata(Tensor(a!) decoder) -> str");
   m.def(
       "get_stream_json_metadata(Tensor(a!) decoder, int stream_index) -> str");
   m.def("_get_json_ffmpeg_library_versions() -> str");
   m.def(
-      "_test_frame_pts_equality(Tensor(a!) decoder, *, int stream_index, int frame_index, float pts_seconds_to_test) -> bool");
+      "_test_frame_pts_equality(Tensor(a!) decoder, *, int frame_index, float pts_seconds_to_test) -> bool");
   m.def("scan_all_streams_to_update_metadata(Tensor(a!) decoder) -> ()");
 }
 
@@ -245,18 +244,14 @@ OpsFrameOutput get_frame_at_pts(at::Tensor& decoder, double seconds) {
   return makeOpsFrameOutput(result);
 }
 
-OpsFrameOutput get_frame_at_index(
-    at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
-    int64_t frame_index) {
+OpsFrameOutput get_frame_at_index(at::Tensor& decoder, int64_t frame_index) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
   auto result = videoDecoder->getFrameAtIndex(frame_index);
   return makeOpsFrameOutput(result);
 }
 
 OpsFrameBatchOutput get_frames_at_indices(
     at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
     at::IntArrayRef frame_indices) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
   std::vector<int64_t> frameIndicesVec(
@@ -267,7 +262,6 @@ OpsFrameBatchOutput get_frames_at_indices(
 
 OpsFrameBatchOutput get_frames_in_range(
     at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
     int64_t start,
     int64_t stop,
     std::optional<int64_t> step) {
@@ -278,7 +272,6 @@ OpsFrameBatchOutput get_frames_in_range(
 
 OpsFrameBatchOutput get_frames_by_pts(
     at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
     at::ArrayRef<double> timestamps) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
   std::vector<double> timestampsVec(timestamps.begin(), timestamps.end());
@@ -288,7 +281,6 @@ OpsFrameBatchOutput get_frames_by_pts(
 
 OpsFrameBatchOutput get_frames_by_pts_in_range(
     at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
     double start_seconds,
     double stop_seconds) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
@@ -321,17 +313,14 @@ std::string mapToJson(const std::map<std::string, std::string>& metadataMap) {
 
 bool _test_frame_pts_equality(
     at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index,
     int64_t frame_index,
     double pts_seconds_to_test) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
   return pts_seconds_to_test ==
       videoDecoder->getPtsSecondsForFrame(frame_index);
 }
 
-torch::Tensor _get_key_frame_indices(
-    at::Tensor& decoder,
-    [[maybe_unused]] int64_t stream_index) {
+torch::Tensor _get_key_frame_indices(at::Tensor& decoder) {
   auto videoDecoder = unwrapTensorToGetDecoder(decoder);
   return videoDecoder->getKeyFrameIndices();
 }

src/torchcodec/decoders/_core/VideoDecoderOps.h

@@ -85,14 +85,10 @@ OpsFrameOutput get_frame_at_pts(at::Tensor& decoder, double seconds);
 // Return the frames at given ptss for a given stream
 OpsFrameBatchOutput get_frames_by_pts(
     at::Tensor& decoder,
-    int64_t stream_index,
     at::ArrayRef<double> timestamps);
 
 // Return the frame that is visible at a given index in the video.
-OpsFrameOutput get_frame_at_index(
-    at::Tensor& decoder,
-    int64_t stream_index,
-    int64_t frame_index);
+OpsFrameOutput get_frame_at_index(at::Tensor& decoder, int64_t frame_index);
 
 // Get the next frame from the video as a tuple that has the frame data, pts and
 // duration as tensors.
@@ -101,14 +97,12 @@ OpsFrameOutput get_next_frame(at::Tensor& decoder);
 // Return the frames at given indices for a given stream
 OpsFrameBatchOutput get_frames_at_indices(
     at::Tensor& decoder,
-    int64_t stream_index,
     at::IntArrayRef frame_indices);
 
 // Return the frames inside a range as a single stacked Tensor. The range is
 // defined as [start, stop).
 OpsFrameBatchOutput get_frames_in_range(
     at::Tensor& decoder,
-    int64_t stream_index,
     int64_t start,
     int64_t stop,
     std::optional<int64_t> step = std::nullopt);
@@ -118,7 +112,6 @@ OpsFrameBatchOutput get_frames_in_range(
 // order.
 OpsFrameBatchOutput get_frames_by_pts_in_range(
     at::Tensor& decoder,
-    int64_t stream_index,
     double start_seconds,
     double stop_seconds);
 
@@ -128,16 +121,15 @@ OpsFrameBatchOutput get_frames_by_pts_in_range(
 // We want to make sure that the value is preserved exactly, bit-for-bit, during
 // this process.
 //
-// Returns true if for the given decoder, in the stream stream_index, the pts
+// Returns true if for the given decoder, the pts
 // value when converted to seconds as a double is exactly pts_seconds_to_test.
 // Returns false otherwise.
 bool _test_frame_pts_equality(
     at::Tensor& decoder,
-    int64_t stream_index,
     int64_t frame_index,
     double pts_seconds_to_test);
 
-torch::Tensor _get_key_frame_indices(at::Tensor& decoder, int64_t stream_index);
+torch::Tensor _get_key_frame_indices(at::Tensor& decoder);
 
 // Get the metadata from the video as a string.
 std::string get_json_metadata(at::Tensor& decoder);

src/torchcodec/decoders/_video_decoder.py

@@ -152,9 +152,7 @@ def _getitem_int(self, key: int) -> Tensor:
                 f"Index {key} is out of bounds; length is {self._num_frames}"
             )
 
-        frame_data, *_ = core.get_frame_at_index(
-            self._decoder, frame_index=key, stream_index=self.stream_index
-        )
+        frame_data, *_ = core.get_frame_at_index(self._decoder, frame_index=key)
         return frame_data
 
     def _getitem_slice(self, key: slice) -> Tensor:
@@ -163,7 +161,6 @@ def _getitem_slice(self, key: slice) -> Tensor:
         start, stop, step = key.indices(len(self))
         frame_data, *_ = core.get_frames_in_range(
             self._decoder,
-            stream_index=self.stream_index,
             start=start,
             stop=stop,
             step=step,
@@ -189,9 +186,7 @@ def __getitem__(self, key: Union[numbers.Integral, slice]) -> Tensor:
         )
 
     def _get_key_frame_indices(self) -> list[int]:
-        return core._get_key_frame_indices(
-            self._decoder, stream_index=self.stream_index
-        )
+        return core._get_key_frame_indices(self._decoder)
 
     def get_frame_at(self, index: int) -> Frame:
         """Return a single frame at the given index.
@@ -208,7 +203,7 @@ def get_frame_at(self, index: int) -> Frame:
                 f"Index {index} is out of bounds; must be in the range [0, {self._num_frames})."
             )
         data, pts_seconds, duration_seconds = core.get_frame_at_index(
-            self._decoder, frame_index=index, stream_index=self.stream_index
+            self._decoder, frame_index=index
         )
         return Frame(
             data=data,
@@ -234,7 +229,7 @@ def get_frames_at(self, indices: list[int]) -> FrameBatch:
         """
 
         data, pts_seconds, duration_seconds = core.get_frames_at_indices(
-            self._decoder, stream_index=self.stream_index, frame_indices=indices
+            self._decoder, frame_indices=indices
         )
         return FrameBatch(
             data=data,
@@ -268,7 +263,6 @@ def get_frames_in_range(self, start: int, stop: int, step: int = 1) -> FrameBatc
             raise IndexError(f"Step ({step}) must be greater than 0.")
         frames = core.get_frames_in_range(
             self._decoder,
-            stream_index=self.stream_index,
             start=start,
             stop=stop,
             step=step,
@@ -316,7 +310,7 @@ def get_frames_played_at(self, seconds: list[float]) -> FrameBatch:
             FrameBatch: The frames that are played at ``seconds``.
         """
         data, pts_seconds, duration_seconds = core.get_frames_by_pts(
-            self._decoder, timestamps=seconds, stream_index=self.stream_index
+            self._decoder, timestamps=seconds
         )
         return FrameBatch(
             data=data,
@@ -359,7 +353,6 @@ def get_frames_played_in_range(
             )
         frames = core.get_frames_by_pts_in_range(
             self._decoder,
-            stream_index=self.stream_index,
             start_seconds=start_seconds,
             stop_seconds=stop_seconds,
         )

test/decoders/manual_smoke_test.py

@@ -16,7 +16,5 @@
 )
 torchcodec.decoders._core.scan_all_streams_to_update_metadata(decoder)
 torchcodec.decoders._core.add_video_stream(decoder, stream_index=3)
-frame, _, _ = torchcodec.decoders._core.get_frame_at_index(
-    decoder, stream_index=3, frame_index=180
-)
+frame, _, _ = torchcodec.decoders._core.get_frame_at_index(decoder, frame_index=180)
 write_png(frame, "frame180.png")