## Summary
Removes the deprecated `hls_acodec` and `hls_vcodec` configuration
options and implements automatic codec detection for HLS streams, fixing
issues with video-only streams incorrectly showing audio information.
## Problem
- When streaming video-only content via RTMP, HLS output incorrectly
contained audio track information due to hardcoded default codec
settings
- The static `hls_acodec` and `hls_vcodec` configurations were
inflexible and caused compatibility issues with some players
- Users had to manually configure `hls_acodec an` to fix video-only
streams
## Solution
- **Remove deprecated configs**: Eliminates `hls_acodec` and
`hls_vcodec` configuration options entirely
- **Dynamic codec detection**: HLS muxer now automatically detects and
uses actual stream codecs in real-time
- **Improved defaults**: Changes from hardcoded AAC/H.264 defaults to
disabled state, letting actual stream content determine codec
information
- **Real-time codec switching**: Supports codec changes during streaming
with proper logging
## Changes
- Remove `get_hls_acodec()` and `get_hls_vcodec()` from SrsConfig
- Update HLS muxer to use `latest_acodec_`/`latest_vcodec_` for codec
detection
- Add codec detection logic in `write_audio()` and `write_video()`
methods
- Remove deprecated config options from all configuration files
- Add comprehensive unit tests for codec detection functionality
Fixes#4223
---------
Co-authored-by: Haibo Chen <495810242@qq.com>
Co-authored-by: OSSRS-AI <winlinam@gmail.com>
