Enable local builds with FFmpeg8 (#935)

Co-authored-by: Daniel Flores <[email protected]>

Author: Dan-Flores

src/torchcodec/_core/CMakeLists.txt

@@ -304,6 +304,8 @@ else()
         set(ffmpeg_major_version "6")
     elseif (${libavcodec_major_version} STREQUAL "61")
         set(ffmpeg_major_version "7")
+    elseif (${libavcodec_major_version} STREQUAL "62")
+        set(ffmpeg_major_version "8")
     else()
         message(
             FATAL_ERROR

src/torchcodec/_core/FFMPEGCommon.cpp

@@ -8,6 +8,11 @@
 
 #include <c10/util/Exception.h>
 
+extern "C" {
+#include <libavfilter/avfilter.h>
+#include <libavfilter/buffersink.h>
+}
+
 namespace facebook::torchcodec {
 
 AutoAVPacket::AutoAVPacket() : avPacket_(av_packet_alloc()) {
@@ -374,6 +379,70 @@ SwrContext* createSwrContext(
   return swrContext;
 }
 
+AVFilterContext* createBuffersinkFilter(
+    AVFilterGraph* filterGraph,
+    enum AVPixelFormat outputFormat) {
+  const AVFilter* buffersink = avfilter_get_by_name("buffersink");
+  TORCH_CHECK(buffersink != nullptr, "Failed to get buffersink filter.");
+
+  AVFilterContext* sinkContext = nullptr;
+  int status;
+  const char* filterName = "out";
+
+  enum AVPixelFormat pix_fmts[] = {outputFormat, AV_PIX_FMT_NONE};
+
+// av_opt_set_int_list was replaced by av_opt_set_array() in FFmpeg 8.
+#if LIBAVUTIL_VERSION_MAJOR >= 60 // FFmpeg >= 8
+  // Output options like pixel_formats must be set before filter init
+  sinkContext =
+      avfilter_graph_alloc_filter(filterGraph, buffersink, filterName);
+  TORCH_CHECK(
+      sinkContext != nullptr, "Failed to allocate buffersink filter context.");
+
+  // When setting pix_fmts, only the first element is used, so nb_elems = 1
+  // AV_PIX_FMT_NONE acts as a terminator for the array in av_opt_set_int_list
+  status = av_opt_set_array(
+      sinkContext,
+      "pixel_formats",
+      AV_OPT_SEARCH_CHILDREN,
+      0, // start_elem
+      1, // nb_elems
+      AV_OPT_TYPE_PIXEL_FMT,
+      pix_fmts);
+  TORCH_CHECK(
+      status >= 0,
+      "Failed to set pixel format for buffersink filter: ",
+      getFFMPEGErrorStringFromErrorCode(status));
+
+  status = avfilter_init_str(sinkContext, nullptr);
+  TORCH_CHECK(
+      status >= 0,
+      "Failed to initialize buffersink filter: ",
+      getFFMPEGErrorStringFromErrorCode(status));
+#else // FFmpeg <= 7
+  // For older FFmpeg versions, create filter and then set options
+  status = avfilter_graph_create_filter(
+      &sinkContext, buffersink, filterName, nullptr, nullptr, filterGraph);
+  TORCH_CHECK(
+      status >= 0,
+      "Failed to create buffersink filter: ",
+      getFFMPEGErrorStringFromErrorCode(status));
+
+  status = av_opt_set_int_list(
+      sinkContext,
+      "pix_fmts",
+      pix_fmts,
+      AV_PIX_FMT_NONE,
+      AV_OPT_SEARCH_CHILDREN);
+  TORCH_CHECK(
+      status >= 0,
+      "Failed to set pixel formats for buffersink filter: ",
+      getFFMPEGErrorStringFromErrorCode(status));
+#endif
+
+  return sinkContext;
+}
+
 UniqueAVFrame convertAudioAVFrameSamples(
     const UniqueSwrContext& swrContext,
     const UniqueAVFrame& srcAVFrame,

src/torchcodec/_core/FFMPEGCommon.h

@@ -237,4 +237,8 @@ int64_t computeSafeDuration(
     const AVRational& frameRate,
     const AVRational& timeBase);
 
+AVFilterContext* createBuffersinkFilter(
+    AVFilterGraph* filterGraph,
+    enum AVPixelFormat outputFormat);
+
 } // namespace facebook::torchcodec

src/torchcodec/_core/FilterGraph.cpp

@@ -5,6 +5,7 @@
 // LICENSE file in the root directory of this source tree.
 
 #include "src/torchcodec/_core/FilterGraph.h"
+#include "src/torchcodec/_core/FFMPEGCommon.h"
 
 extern "C" {
 #include <libavfilter/buffersink.h>
@@ -63,7 +64,6 @@ FilterGraph::FilterGraph(
   }
 
   const AVFilter* buffersrc = avfilter_get_by_name("buffer");
-  const AVFilter* buffersink = avfilter_get_by_name("buffersink");
 
   UniqueAVBufferSrcParameters srcParams(av_buffersrc_parameters_alloc());
   TORCH_CHECK(srcParams, "Failed to allocate buffersrc params");
@@ -93,26 +93,10 @@ FilterGraph::FilterGraph(
       "Failed to create filter graph : ",
       getFFMPEGErrorStringFromErrorCode(status));
 
-  status = avfilter_graph_create_filter(
-      &sinkContext_, buffersink, "out", nullptr, nullptr, filterGraph_.get());
+  sinkContext_ =
+      createBuffersinkFilter(filterGraph_.get(), filtersContext.outputFormat);
   TORCH_CHECK(
-      status >= 0,
-      "Failed to create filter graph: ",
-      getFFMPEGErrorStringFromErrorCode(status));
-
-  enum AVPixelFormat pix_fmts[] = {
-      filtersContext.outputFormat, AV_PIX_FMT_NONE};
-
-  status = av_opt_set_int_list(
-      sinkContext_,
-      "pix_fmts",
-      pix_fmts,
-      AV_PIX_FMT_NONE,
-      AV_OPT_SEARCH_CHILDREN);
-  TORCH_CHECK(
-      status >= 0,
-      "Failed to set output pixel formats: ",
-      getFFMPEGErrorStringFromErrorCode(status));
+      sinkContext_ != nullptr, "Failed to create and configure buffersink");
 
   UniqueAVFilterInOut outputs(avfilter_inout_alloc());
   UniqueAVFilterInOut inputs(avfilter_inout_alloc());

src/torchcodec/_core/ops.py

@@ -41,7 +41,7 @@ def load_torchcodec_shared_libraries():
     #      libraries do not meet those conditions.
 
     exceptions = []
-    for ffmpeg_major_version in (7, 6, 5, 4):
+    for ffmpeg_major_version in (8, 7, 6, 5, 4):
         pybind_ops_module_name = _get_pybind_ops_module_name(ffmpeg_major_version)
         decoder_library_name = f"libtorchcodec_core{ffmpeg_major_version}"
         custom_ops_library_name = f"libtorchcodec_custom_ops{ffmpeg_major_version}"