Reproduces a segment seeking bug and memory leak in nvcodec

Dockerfile

FROM nvidia/cuda:11.2.1-devel-ubuntu18.04 AS gstreamer

# Adds NVCODEC libraries to the environment for use in building NVDEC support
ENV NVIDIA_DRIVER_CAPABILITIES=all

ARG FFMPEG_VERSION=n4.3.1

WORKDIR /ffmpeg
# Get FFmpeg dependencies
RUN apt-get update && \
    apt-get -y --no-install-recommends install \
        autoconf automake build-essential libtool libxcb1-dev \
        libxcb-shm0-dev libxcb-xfixes0-dev texinfo zlib1g-dev yasm git \
        ca-certificates \
        && \
    rm -rf /var/lib/apt/lists/*
RUN update-ca-certificates && \
    git clone --depth=1 --branch=$FFMPEG_VERSION https://github.com/FFmpeg/FFmpeg .
# Build
RUN ./configure \
  --enable-shared \
  --extra-libs="-lpthread -lm" \
  --disable-static
RUN make -j $(($(nproc) + 1))
RUN make install

# Get GStreamer build dependencies
RUN apt-get update && \
    apt-get -y --no-install-recommends install \
        # Generic build dependencies
        pkg-config autopoint libglib2.0-dev gettext wget \
        ca-certificates git g++ yasm ninja-build flex bison \
        libgirepository1.0-dev gobject-introspection \
        # gst-plugins-base dependencies
        libogg0 libopus0 libtheora0 libvorbis0a libvorbisenc2 \
        # gst-plugins-good dependencies
        libv4l-dev libjpeg-dev libmp3lame-dev libmpg123-dev \
        libtag1-dev libvpx-dev nettle-dev \
	# gst-libav dependencies
	libavcodec-dev libavdevice-dev libavfilter-dev libavformat-dev libavresample-dev libavutil-dev \
        # gst-plugins-bad dependencies
        libsoup2.4-dev \
        # Pip, so we can install Meson
        python3-pip python3-setuptools \
        # For JIT acceleration
        liborc-0.4-dev \
        && \
    rm -rf /var/lib/apt/lists/*
RUN pip3 install --no-cache-dir meson==0.55.3

ARG GSTREAMER_VERSION=1.19.1

# Build GStreamer core
WORKDIR /gstreamer
RUN update-ca-certificates && \
    git clone --depth 1 --branch $GSTREAMER_VERSION https://gitlab.freedesktop.org/gstreamer/gstreamer
WORKDIR /gstreamer/gstreamer
RUN meson builddir
RUN ninja -C builddir install

# Build base GStreamer plugins
WORKDIR /gstreamer
RUN update-ca-certificates && \
    git clone --depth 1 --branch $GSTREAMER_VERSION https://gitlab.freedesktop.org/gstreamer/gst-plugins-base
WORKDIR /gstreamer/gst-plugins-base
RUN meson builddir
RUN ninja -C builddir install

# Build good GStreamer plugins
WORKDIR /gstreamer
RUN update-ca-certificates && \
    git clone --depth 1 --branch $GSTREAMER_VERSION https://gitlab.freedesktop.org/gstreamer/gst-plugins-good
WORKDIR /gstreamer/gst-plugins-good
RUN meson builddir
RUN ninja -C builddir install

# Build only a few "bad" GStreamer plugins
WORKDIR /gstreamer
RUN update-ca-certificates && \
    git clone --depth 1 --branch $GSTREAMER_VERSION https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad
WORKDIR /gstreamer/gst-plugins-bad
RUN meson builddir
RUN meson configure \
    # Disable all plugins by default
    -Dauto_features=disabled \
    # h264parse, required for NVDEC to work
    -Dvideoparsers=enabled \
    # NVDEC hardware decoding
    -Dnvcodec=enabled \
    builddir
RUN ninja -C builddir install

# Build GStreamer libav support
WORKDIR /gstreamer
RUN update-ca-certificates && \
    git clone --depth 1 --branch $GSTREAMER_VERSION https://gitlab.freedesktop.org/gstreamer/gst-libav
WORKDIR /gstreamer/gst-libav
RUN meson builddir
RUN ninja -C builddir install

WORKDIR /project
RUN apt-get update && \
    apt-get -y --no-install-recommends install \
        python3-dev python3-wheel libcairo-dev libgirepository1.0-dev \
        && \
    rm -rf /var/lib/apt/lists/*
RUN pip3 install pygobject

ENV GI_TYPELIB_PATH="/usr/local/lib/x86_64-linux-gnu/girepository-1.0"
ENV GST_DEBUG=3

COPY reproducer.py .
COPY test_video.mp4 .

CMD [ "python3", "/project/reproducer.py", "/project/test_video.mp4" ]

reproducer.py

from threading import Thread
from time import sleep
import sys

import gi

gi.require_version("Gst", "1.0")
gi.require_version("GstApp", "1.0")

from gi.repository import Gst, GLib, GstApp


def main():
    if len(sys.argv) < 2:
        print("Usage: python3 reproducer.py {video file}")
        sys.exit(1)

    Gst.init()

    main_loop = GLib.MainLoop.new(context=None, is_running=False)
    main_loop_thread = Thread(
        target=main_loop.run, name="GObjectInitThread", daemon=True
    )
    main_loop_thread.start()

    pipeline = Gst.parse_launch(
        f"filesrc location={sys.argv[1]} "
        "! qtdemux "
        "! h264parse "
        "! nvh264dec "
        "! fakesink "
    )

    segment_seeking_on = False

    def watch(_bus, message):
        nonlocal segment_seeking_on

        if message.type == Gst.MessageType.STATE_CHANGED:
            _, new_state, _ = message.parse_state_changed()
            if (
                message.src == pipeline
                and new_state == Gst.State.PLAYING
                and not segment_seeking_on
            ):
                print("Enabling segment seeking")
                _segment_seek_to_start(pipeline, flush=True)
                segment_seeking_on = True
        elif message.type == Gst.MessageType.SEGMENT_DONE:
            print("Seeking back to the start of the video")
            _segment_seek_to_start(pipeline, flush=False)

        return True

    pipeline.get_bus().add_watch(GLib.PRIORITY_DEFAULT, watch)

    pipeline.set_state(Gst.State.PLAYING)
    print("Requested the PLAYING state")

    try:
        while True:
            sleep(0.1)
    except KeyboardInterrupt:
        pass

    print("Done")


def _segment_seek_to_start(pipeline, flush):
    """Seeks the given pipeline to the start of the video stream. This should
    be done as a response to a SEGMENT_DONE event.
    """
    flags = Gst.SeekFlags.SEGMENT
    if flush:
        flags |= Gst.SeekFlags.FLUSH

    seek_result = pipeline.seek(
        rate=1.0,
        format=Gst.Format.TIME,
        flags=flags,
        start_type=Gst.SeekType.SET,
        start=0,
        stop_type=Gst.SeekType.NONE,
        stop=-1,
    )
    if not seek_result:
        raise RuntimeError(f"Failed to send seek event")


if __name__ == "__main__":
    main()


_ = GstApp