more infos about copy mode

docs/stream_copy.md

@@ -2,7 +2,7 @@
 
 ffplayout supports a stream copy mode since v0.20.0. A separate copy mode for video and audio is possible. This mode uses less CPU and RAM, but has some drawbacks:
 
-- All files must have exactly the same resolution, color depth, audio channels and kHz.
+- All files must have exactly the same resolution, framerate, color depth, audio channels and kHz.
 - All files must use the same codecs and settings.
 - The video and audio lines of a file must be the same length.
 - The codecs and A/V settings must be supported by mpegts and the output destination.

lib/src/filter/mod.rs

@@ -573,7 +573,7 @@ pub fn filter_chains(
             custom(&list_af, &mut filters, i, Audio);
         }
     } else if config.processing.audio_track_index > -1 {
-        error!("Setting audio_track_index other than -1 is not allowed in audio copy mode!")
+        error!("Setting 'audio_track_index' other than '-1' is not allowed in audio copy mode!")
     }
 
     if config.out.mode == HLS {