Hello,
I have a streaming app I wrote that started from the transcode example
and grew.
So I'm trying to add subtitle support now, and it mostly works. From a
file that contains subtitles, I get valid subtitle packets with
avPacket->data that contains valid text and webvtt outputs valid data.
However, another type of input I am trying to reproduce is from this
ffmpeg command that I use that works to extract video/audio and
subtitles from a local tv station tuner pickup.
ffmpeg -f lavfi -i
movie=/dev/dvb/adapter0/dvr0:f=mpegts:s=dv+da[out0+subcc][out1] test.mkv
So the only difference in my code was the addition of:
avdevice_register_all();
And finding the lavfi input format:
in_format = av_find_input_format("lavfi");
And passing the format to the avformat_open_input function.
The video and audio comes out just fine, but the subtitle packets all
have a length of 30 bytes, and the data appears to be garbage (well,
could be raw data I've not explored that).
The only thing I can think of is the need for something unique when
setting up the AVCodecContext for the subtitle besides just
const AVCodec *dec =
avcodec_find_decoder(dec_stream->codecpar->codec_id)
AVCodecContext *codec_ctx = avcodec_alloc_context3(dec)
avcodec_parameters_to_context(codec_ctx, dec_stream->codecpar)
avcodec_open2(codec_ctx, dec, NULL);
Thanks for any hints!
Deron
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