- Posts: 2
- Joined: Wed Jul 24, 2019 3:41 pm
- Real Name: Bart Trojanowski
Hi,
I am using a 'DeckLink Duo 2' card, and would like to pass captions from a UDP stream with ffmpeg out to SDI with captions.
I realize this is an ffmpeg question, but I'm hoping that someone here has experience as documentation of this specific problem is lacking.
I can see in ffmepg's "libavdevice/decklink_enc.cpp" that construct_cc() has the code to encode the captions and pass them to the decklink device.
I'm running "master" of ffmpeg from about 3 months ago (255feeccc5), with blackmagic SDK 11.1. I've built my ffmpeg with:
The command I've attempted to use:
The output contains:
So far things look good, but ffmpeg dies with:
This is generated by ff_decklink_write_header() where the "Setup streams" loop does not handle "c->codec_type == AVMEDIA_TYPE_SUBTITLE".
So, I'm at a loss. While the construct_cc() functions suggests that captions are supported, I'm clearly not connecting them through the graph correctly.
Any help would be appreciated.
I am using a 'DeckLink Duo 2' card, and would like to pass captions from a UDP stream with ffmpeg out to SDI with captions.
I realize this is an ffmpeg question, but I'm hoping that someone here has experience as documentation of this specific problem is lacking.
I can see in ffmepg's "libavdevice/decklink_enc.cpp" that construct_cc() has the code to encode the captions and pass them to the decklink device.
I'm running "master" of ffmpeg from about 3 months ago (255feeccc5), with blackmagic SDK 11.1. I've built my ffmpeg with:
- Code: Select all
--enable-encoders --enable-decoders --enable-vaapi --enable-libzvbi --enable-libklvanc --enable-nvenc --enable-nvdec --enable-vdpau --enable-cuvid --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-decklink
The command I've attempted to use:
- Code: Select all
ffmpeg -i 'udp://127.0.0.1:8888/?buffer_size=1048576' -map 0:0 -map 0:1 -map 0:2 -teletext_lines all -c:s copy -f decklink -vframes 10 -pix_fmt uyvy422 'DeckLink Duo (3)'
The output contains:
- Code: Select all
Program 1
Metadata:
service_name : Service01
service_provider: FFmpeg
Stream #0:0[0x100], 12, 1/90000: Video: hevc (Rext), 1 reference frame (HEVC / 0x43564548), yuv444p(tv), 1280x720 (1280x736) [SAR 1:1 DAR 16:9], 0/1, Closed Captions, 59.94 fps, 59.94 tbr, 90k tbn, 59.94 tbc
Stream #0:1[0x101], 10, 1/90000: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 384 kb/s
Stream #0:2[0x102](und), 0, 1/90000: Subtitle: dvb_teletext ([6][0][0][0] / 0x0006)
- Code: Select all
Stream mapping:
Stream #0:0 -> #0:0 (hevc (native) -> wrapped_avframe (native))
Stream #0:1 -> #0:1 (mp2 (native) -> pcm_s16le (native))
Stream #0:2 -> #0:2 (copy)
So far things look good, but ffmpeg dies with:
- Code: Select all
[decklink @ 0x55bda32d5d00] Unsupported stream type.
This is generated by ff_decklink_write_header() where the "Setup streams" loop does not handle "c->codec_type == AVMEDIA_TYPE_SUBTITLE".
So, I'm at a loss. While the construct_cc() functions suggests that captions are supported, I'm clearly not connecting them through the graph correctly.
Any help would be appreciated.