This example demonstrates video decoding using the rocDecode library's built-in bitstream reader instead of FFMPEG demuxer. The sample reads raw video bitstreams directly and decodes them using hardware acceleration, providing an alternative to FFMPEG-based demuxing. This approach is useful for scenarios where FFMPEG is not available or when working with raw elementary streams.

1. Parse command-line arguments for input file, device ID, and output options.
2. Create the built-in bitstream reader using rocDecCreateBitstreamReader().
3. Extract codec information from the bitstream.
4. Create the video decoder instance with the detected codec.
5. Verify codec support on the selected GPU device.
6. Loop through bitstream:
   • Read video data packets using the bitstream reader.
   • Parse packets using the video parser.
   • Decode frames through parser callbacks.
   • Retrieve decoded frames.
   • Optionally save frames to output file.
7. Display decoding statistics.
8. Destroy bitstream reader and clean up decoder resources.

• Built-in Bitstream Reader: rocDecode provides a native bitstream reader:

  • rocDecCreateBitstreamReader(): Creates a reader for raw elementary streams.
  • rocDecDestroyBitstreamReader(): Releases bitstream reader resources.
  • Eliminates dependency on FFMPEG for simple decode scenarios.
  • Supports common video codecs (H.264, HEVC, VP9, AV1).

• Raw Elementary Stream Processing: The bitstream reader handles:

  • Direct reading of compressed video data.
  • Automatic detection of codec type from bitstream.
  • Extraction of sequence parameters and frame data.
  • No container format parsing required.

• Decoder Integration: The decoder works with the bitstream reader:

  • rocDecCreateDecoder(): Initializes decoder with codec from bitstream.
  • rocDecParseVideoData(): Parses data provided by bitstream reader.
  • rocDecDecodeFrame(): Decodes frames using hardware acceleration.
  • Same decode pipeline as FFMPEG-based samples.

• Use Cases:

  • Decoding raw elementary streams without container formats.
  • Embedded systems where FFMPEG is not available.
  • Custom video processing pipelines.
  • Testing decoder with raw bitstream data.
  • Scenarios requiring minimal dependencies.

• Limitations:

  • Only supports elementary streams (no container formats like MP4, MKV).
  • Limited metadata extraction compared to FFMPEG.
  • No support for multiplexed audio/video streams.
  • Codec must be detectable from bitstream headers.

• rocDecCreateDecoder
• rocDecDecodeFrame
• rocDecGetVideoFrame
• rocDecGetDecodeStatus
• rocDecDestroyDecoder
• rocDecCreateVideoParser
• rocDecParseVideoData
• rocDecDestroyVideoParser
• rocDecCreateBitstreamReader
• rocDecDestroyBitstreamReader
• rocDecGetErrorName

• hipSetDevice
• hipGetDeviceProperties
• hipMalloc
• hipFree
• hipMemcpy
• hipMemcpyDtoH

• rocDecDecoderHandle
• RocdecVideoParser
• rocDecVideoCodec
• rocDecVideoSurfaceFormat
• rocDecVideoChromaFormat
• rocDecDecoderCreateInfo
• RocdecParserParams
• RocdecVideoFormat
• RocdecPicParams
• RocdecParserDispInfo
• rocDecDecodeStatus