feat: 视频封面生成 + 视频倒放 + 贴纸叠加三个渲染能力

apps/worker/video_processing/render_audio.py

@@ -22,6 +22,7 @@ from pathlib import Path
 from typing import TYPE_CHECKING
 
 from video_processing.ffmpeg_utils import FFMPEG_BIN, probe_has_audio, run_ffmpeg
+from video_processing.reverse_engine import ReverseConfig, ReverseEngine
 
 if TYPE_CHECKING:
     from video_processing.unified_render_service import RenderLayer, ResolvedClip
@@ -230,6 +231,14 @@ def concat_main_audio(
         if video_duration > 0 and (final_duration <= 0 or final_duration > video_duration):
             final_duration = video_duration
 
+        # 音频倒放
+        reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
+        af_filters = []
+        if reverse_config.enabled and reverse_config.reverse_audio:
+            reverse_filter = ReverseEngine.build_audio_filter(reverse_config, duration=effective_duration)
+            if reverse_filter:
+                af_filters.append(reverse_filter)
+
         command = [
             FFMPEG_BIN,
             "-y",
@@ -243,6 +252,8 @@ def concat_main_audio(
         ]
         if trim_start > 0:
             command.extend(["-ss", f"{trim_start:.3f}"])
+        if af_filters:
+            command.extend(["-af", ",".join(af_filters)])
         if final_duration > 0:
             command.extend(["-t", f"{final_duration:.3f}"])
         command.append(str(output_path))
@@ -257,12 +268,21 @@ def concat_main_audio(
         input_args.extend(["-i", str(clip.local_path)])
         effective_duration = clip_effective_duration(clip)
         trim_start = getattr(clip, "start_time", 0) or 0
+        audio_filters: list[str] = []
         if effective_duration > 0:
-            filter_parts.append(
-                f"[{i}:a]atrim=start={trim_start:.3f}:duration={effective_duration:.3f}," f"asetpts=PTS-STARTPTS[a{i}]"
-            )
+            audio_filters.append(f"atrim=start={trim_start:.3f}:duration={effective_duration:.3f}")
+            audio_filters.append("asetpts=PTS-STARTPTS")
         else:
-            filter_parts.append(f"[{i}:a]asetpts=PTS-STARTPTS[a{i}]")
+            audio_filters.append("asetpts=PTS-STARTPTS")
+
+        # 音频倒放
+        reverse_config = ReverseConfig.from_dict(clip.config.get("reverse"))
+        if reverse_config.enabled and reverse_config.reverse_audio:
+            reverse_filter = ReverseEngine.build_audio_filter(reverse_config, duration=effective_duration)
+            if reverse_filter:
+                audio_filters.append(reverse_filter)
+
+        filter_parts.append(f"[{i}:a]{','.join(audio_filters)}[a{i}]")
 
     audio_labels = "".join(f"[a{i}]" for i in range(len(clips)))
     filter_parts.append(f"{audio_labels}concat=n={len(clips)}:v=0:a=1[outa]")