[mgtv] add bsf:a aac_adtstoasc to ffmpeg params, fix #1458.
diff --git a/src/you_get/processor/ffmpeg.py b/src/you_get/processor/ffmpeg.py
index 1c0ba1a3de..dcc8e1c86d 100644
--- a/src/you_get/processor/ffmpeg.py
+++ b/src/you_get/processor/ffmpeg.py
@@ -125,7 +125,7 @@ def ffmpeg_concat_flv_to_mp4(files, output='output.mp4'):
 
         params = [FFMPEG] + LOGLEVEL + ['-f', 'concat', '-safe', '-1', '-y', '-i']
         params.append(output + '.txt')
-        params += ['-c', 'copy', output]
+        params += ['-c', 'copy', '-bsf:a', 'aac_adtstoasc', output]
 
         subprocess.check_call(params)
         os.remove(output + '.txt')

Add `'-bsf:a', 'aac_adtstoasc'` params to ffmpeg, solves #1458 . I have manually tested this with some other video sites which use `ffmpeg_concat_flv_to_mp4()` and it seems everything works fine, the bsf param have no side effect.

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