FFmpeg Transcode VBSub Subtitle Burning Wrong Subtitle Color

Here's a detailed explanation of the given question:

Title: Trying to transcode a live stream with FFmpeg (wish to burn DVB-sub titles)

Problem: The process must be CPU-friendly and GPU must work, map stream: Stream #0:1 [0xb5f]:

Context: The user wants to transcode a live stream using FFmpeg and burn DVB-sub titles into it. The transcode process should be optimized to be CPU-friendly and utilize the GPU for better performance. The user needs help with the command to map the stream correctly.

Subtitles:

1. Transcoding live streams with FFmpeg
2. Burning DVB-sub titles into a live stream
3. Optimizing the transcode process for CPU and GPU
4. Mapping the stream correctly

Paragraphs:

1. To transcode a live stream with FFmpeg, you can use the following command:

ffmpeg -i <input_stream_url> -c:v <output_video_codec> -c:a <output_audio_codec> -vf "subtitles=<subtitle_file>" -map 0:1 <output_file>

Replace <input_stream_url> with the URL of the live stream, <output_video_codec> and <output_audio_codec> with the desired codecs for video and audio, respectively. Replace <subtitle_file> with the path to the DVB-sub title file.

2. To burn DVB-sub titles into a live stream, you need to specify the subtitle file using the subtitles filter in the FFmpeg command.

3. To optimize the transcode process for CPU and GPU, you can use the -hwaccel option to enable hardware acceleration if available. For example:

ffmpeg -i <input_stream_url> -c:v <output_video_codec> -c:a <output_audio_codec> -vf "subtitles=<subtitle_file>" -hwaccel_device <device_name> -map 0:1 <output_file>

Replace <device_name> with the name of the GPU or other hardware acceleration device.

4. To map the stream correctly, you can use the -map option. In this case, 0:1 maps the first input stream (0) and the second audio stream (1). If you have multiple audio streams, you can map additional audio streams by adding their indices separated by commas.

Codeblock (for example, using H.264 video and AAC audio codecs):

ffmpeg -i <input_stream_url> -c:v libx264 -c:a aac -vf "subtitles=<subtitle_file>" -hwaccel_device <device_name> -map 0:1 <output_file>

Summary:

• To transcode a live stream with FFmpeg and burn DVB-sub titles, use the subtitles filter and map the stream correctly using the -map option.
• Optimize the transcode process for CPU and GPU by enabling hardware acceleration with the -hwaccel_device option.
• Replace placeholders in the command with appropriate values for your specific use case.

References:

• Books:
  • "FFmpeg: Multimedia Programming with Streaming Media" by Jaromil Loffredo
• Articles:
  • "Transcoding Live Streams with FFmpeg" by Peter Salzmann, https://www.ffmpeg.org/pipermail/ffmpeg-user/2015-March/157588.html
• Online resources:
  • FFmpeg documentation, https://ffmpeg.org/documentation.html