build(docker): update Dockerfile and add FFmpeg installation script with Leak Sanitizer support (#14)

- modify Dockerfile to include static files and create videos directory
- update docker-compose to change UDP port range
- add install-ffmpeg-lsan.sh for FFmpeg installation with Leak Sanitizer
- create lsan.Dockerfile for building with Leak Sanitizer

media/streamer/processes/transcoder.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+
 	"liveflow/log"
 	"liveflow/media/streamer/pipe"
 
@@ -68,6 +69,7 @@ func (t *AudioTranscodingProcess) Init() error {
 	if t.encCodecContext == nil {
 		return errors.New("codec context is nil")
 	}
+
 	if t.decCodecContext.MediaType() == astiav.MediaTypeAudio {
 		t.encCodecContext.SetChannelLayout(astiav.ChannelLayoutStereo)
 		t.encCodecContext.SetSampleRate(t.encSampleRate)