tail效果

biz/ffmpeg.py

@@ -27,10 +27,6 @@ def parse_ffmpeg_task(task_info, template_info):
         
         # 统计only_if占位符的使用次数
         only_if_usage_count = {}
-        for part in template_info.get("video_parts", []):
-            only_if = part.get('only_if', '')
-            if only_if:
-                only_if_usage_count[only_if] = only_if_usage_count.get(only_if, 0) + 1
         with tracer.start_as_current_span("parse_ffmpeg_task.download_all") as sub_span:
             with ThreadPoolExecutor(max_workers=8) as executor:
                 param_list: list[dict]
@@ -48,7 +44,8 @@ def parse_ffmpeg_task(task_info, template_info):
                 continue
             only_if = part.get('only_if', '')
             if only_if:
-                required_count = only_if_usage_count.get(only_if, 1)
+                only_if_usage_count[only_if] = only_if_usage_count.get(only_if, 0) + 1
+                required_count = only_if_usage_count.get(only_if)
                 if not check_placeholder_exist_with_count(only_if, task_params_orig, required_count):
                     logger.info("because only_if exist, placeholder: %s insufficient (need %d), skip part: %s", only_if, required_count, part)
                     continue

entity/ffmpeg.py

@@ -308,6 +308,19 @@ class FfmpegTask(object):
                         effect_index += 1
                         filter_args.append(f"{video_output_str}trim=start={skip_seconds},setpts=PTS-STARTPTS[v_eff{effect_index}]")
                         video_output_str = f"[v_eff{effect_index}]"
+                elif effect.startswith("tail:"):
+                    param = effect.split(":", 2)[1]
+                    if param == '':
+                        param = "0"
+                    tail_seconds = float(param)
+                    if tail_seconds > 0:
+                        effect_index += 1
+                        # 首先获取视频总时长，然后计算开始时间
+                        # 使用reverse+trim+reverse的方法来精确获取最后N秒
+                        filter_args.append(f"{video_output_str}reverse[v_rev{effect_index}]")
+                        filter_args.append(f"[v_rev{effect_index}]trim=duration={tail_seconds},setpts=PTS-STARTPTS[v_trim{effect_index}]")
+                        filter_args.append(f"[v_trim{effect_index}]reverse[v_eff{effect_index}]")
+                        video_output_str = f"[v_eff{effect_index}]"
                 ...
             if self.resolution:
                 filter_args.append(f"{video_output_str}scale={self.resolution.replace('x', ':')}[v]")