Update readme about MP4 stream query params

README.md

@@ -880,10 +880,17 @@ API examples:
 
 - MP4 snapshot: `http://192.168.1.123:1984/api/frame.mp4?src=camera1` (H264, H265)
 - MP4 stream: `http://192.168.1.123:1984/api/stream.mp4?src=camera1` (H264, H265, AAC)
-- MP4 file: `http://192.168.1.123:1984/api/stream.mp4?src=camera1&mp4=all&duration=15&filename=record.mp4` (H264, H265*, AAC, OPUS, MP3, PCMA, PCMU, PCM)
+- MP4 file: `http://192.168.1.123:1984/api/stream.mp4?src=camera1` (H264, H265*, AAC, OPUS, MP3, PCMA, PCMU, PCM)
+  - You can use `mp4`, `mp4=flac` and `mp4=all` param for codec filters
+  - You can use `duration` param in seconds (ex. `duration=15`)
+  - You can use `filename` param (ex. `filename=record.mp4`)
+  - You can use `rotate` param with `90`, `180` or `270` values
+  - You can use `scale` param with positive integer values (ex. `scale=4:3`)
 
 Read more about [codecs filters](#codecs-filters).
 
+**PS.** Rotate and scale params don't use transcoding and change video using metadata. 
+
 ### Module: HLS
 
 [HLS](https://en.wikipedia.org/wiki/HTTP_Live_Streaming) is the worst technology for real-time streaming. It can only be useful on devices that do not support more modern technology, like [WebRTC](#module-webrtc), [MSE/MP4](#module-mp4).