lazy-player/lazy_player/thumbnailer.py

134 lines
3.7 KiB
Python

from __future__ import annotations
import multiprocessing
import os
import sys
from concurrent.futures import ThreadPoolExecutor
from queue import LifoQueue
from typing import TYPE_CHECKING, Any, cast
from gi.repository import GLib, Gst
if TYPE_CHECKING:
from .file_model import FileItem
DEFAULT_SEEK_FLAGS = (
Gst.SeekFlags.FLUSH
| Gst.SeekFlags.KEY_UNIT
| Gst.SeekFlags.SNAP_NEAREST
| Gst.SeekFlags.TRICKMODE
| Gst.SeekFlags.TRICKMODE_KEY_UNITS
| Gst.SeekFlags.TRICKMODE_NO_AUDIO
)
__all__ = ["Thumbnailer", "generate_thumbnail_sync"]
MAX_WORKERS = max(1, multiprocessing.cpu_count() // 2)
class Thumbnailer(ThreadPoolExecutor):
def __init__(self):
super().__init__(
thread_name_prefix="Thumbnailer",
max_workers=MAX_WORKERS,
)
self._work_queue = cast(Any, LifoQueue())
def generate_thumbnail(self, file_item: FileItem):
"""Schedule thumbnail generation."""
if not file_item.full_path.is_file():
return
if file_item.attempted_thumbnail.value:
return
self.submit(generate_thumbnail_sync_nicely, file_item)
file_item.attempted_thumbnail.value = True
def generate_thumbnail_sync_nicely(file_item: FileItem):
os.nice(10)
return generate_thumbnail_sync(file_item)
def generate_thumbnail_sync(file_item: FileItem):
"""Generate thumbnail for a single file"""
# print("[thumbnailer] Generate:", file_item.full_path.name)
pipeline_str = (
"uridecodebin name=uridecodebin force-sw-decoders=true ! "
"videoconvert ! "
"jpegenc quality=85 ! "
"appsink sync=false name=sink"
)
pipeline: Gst.Pipeline | None = None
try:
pipeline = cast(Gst.Pipeline, Gst.parse_launch(pipeline_str))
sink = pipeline.get_by_name("sink")
assert isinstance(sink, Gst.Element)
uridecodebin = pipeline.get_by_name("uridecodebin")
assert isinstance(uridecodebin, Gst.Element)
# Set file URI
uridecodebin.set_property("uri", Gst.filename_to_uri(str(file_item.full_path)))
# Set pipeline to PAUSED to get duration
pipeline.set_state(Gst.State.PAUSED)
pipeline.get_state(Gst.CLOCK_TIME_NONE)
# Obtain total duration
success, duration = pipeline.query_duration(Gst.Format.TIME)
if not success:
raise RuntimeError("Failed to query duration")
def get_sample(seek_pos: int) -> bytes:
pipeline.seek_simple(Gst.Format.TIME, DEFAULT_SEEK_FLAGS, seek_pos)
# Start playing to capture frame
pipeline.set_state(Gst.State.PLAYING)
sample = sink.emit("pull-sample")
if not sample:
raise RuntimeError("Failed to pull sample")
# Extract image data
buffer = sample.get_buffer()
if not buffer:
raise RuntimeError("Failed to get buffer")
success, map_info = buffer.map(Gst.MapFlags.READ)
if not success:
raise RuntimeError("Failed to map buffer")
try:
return bytes(map_info.data)
finally:
buffer.unmap(map_info)
candidates: list[bytes] = []
for i in range(3):
candidates.append(get_sample(duration // 3 - Gst.SECOND + i * Gst.SECOND))
thumbnail = max(candidates, key=len)
def set_thumbnail():
file_item.thumbnail.value = thumbnail
GLib.idle_add(set_thumbnail)
except Exception as err:
print("[thumbnailer] Error:", file_item.full_path.name, file=sys.stderr)
print("[thumbnailer]", err, file=sys.stderr)
finally:
if pipeline:
pipeline.set_state(Gst.State.NULL)