Struct ChannelLayout

Source

#[repr(transparent)]
pub struct ChannelLayout(pub AVChannelLayout);

Tuple Fields§

§0: AVChannelLayout

Implementations§

Source §

pub fn channels(&self) -> i32

Examples found in repository ?

examples/transcode-audio.rs (line 92)

64fn transcoder<P: AsRef<Path> + ?Sized>(
65    ictx: &mut format::context::Input,
66    octx: &mut format::context::Output,
67    path: &P,
68    filter_spec: &str,
69) -> Result<Transcoder, ffmpeg::Error> {
70    let input = ictx
71        .streams()
72        .best(media::Type::Audio)
73        .expect("could not find best audio stream");
74    let context = ffmpeg::codec::context::Context::from_parameters(input.parameters())?;
75    let mut decoder = context.decoder().audio()?;
76    let codec = ffmpeg::encoder::find(octx.format().codec(path, media::Type::Audio))
77        .expect("failed to find encoder")
78        .audio()?;
79    let global = octx
80        .format()
81        .flags()
82        .contains(ffmpeg::format::flag::Flags::GLOBAL_HEADER);
83
84    decoder.set_parameters(input.parameters())?;
85
86    let mut output = octx.add_stream(codec)?;
87    let context = ffmpeg::codec::context::Context::from_parameters(output.parameters())?;
88    let mut encoder = context.encoder().audio()?;
89
90    let channel_layout = codec
91        .channel_layouts()
92        .map(|cls| cls.best(decoder.channel_layout().channels()))
93        .unwrap_or(ffmpeg::channel_layout::ChannelLayout::STEREO);
94
95    if global {
96        encoder.set_flags(ffmpeg::codec::flag::Flags::GLOBAL_HEADER);
97    }
98
99    encoder.set_rate(decoder.rate() as i32);
100    encoder.set_channel_layout(channel_layout);
101    #[cfg(not(feature = "ffmpeg_7_0"))]
102    {
103        encoder.set_channels(channel_layout.channels());
104    }
105    encoder.set_format(
106        codec
107            .formats()
108            .expect("unknown supported formats")
109            .next()
110            .unwrap(),
111    );
112    encoder.set_bit_rate(decoder.bit_rate());
113    encoder.set_max_bit_rate(decoder.max_bit_rate());
114
115    encoder.set_time_base((1, decoder.rate() as i32));
116    output.set_time_base((1, decoder.rate() as i32));
117
118    let encoder = encoder.open_as(codec)?;
119    output.set_parameters(&encoder);
120
121    let filter = filter(filter_spec, &decoder, &encoder)?;
122
123    let in_time_base = decoder.time_base();
124    let out_time_base = output.time_base();
125
126    Ok(Transcoder {
127        stream: input.index(),
128        filter,
129        decoder,
130        encoder,
131        in_time_base,
132        out_time_base,
133    })
134}

Source

pub fn bits(&self) -> u64

Examples found in repository ?

examples/transcode-audio.rs (line 21)

9fn filter(
10    spec: &str,
11    decoder: &codec::decoder::Audio,
12    encoder: &codec::encoder::Audio,
13) -> Result<filter::Graph, ffmpeg::Error> {
14    let mut filter = filter::Graph::new();
15
16    let args = format!(
17        "time_base={}:sample_rate={}:sample_fmt={}:channel_layout=0x{:x}",
18        decoder.time_base(),
19        decoder.rate(),
20        decoder.format().name(),
21        decoder.channel_layout().bits()
22    );
23
24    filter.add(&filter::find("abuffer").unwrap(), "in", &args)?;
25    filter.add(&filter::find("abuffersink").unwrap(), "out", "")?;
26
27    {
28        let mut out = filter.get("out").unwrap();
29
30        out.set_sample_format(encoder.format());
31        out.set_channel_layout(encoder.channel_layout());
32        out.set_sample_rate(encoder.rate());
33    }
34
35    filter.output("in", 0)?.input("out", 0)?.parse(spec)?;
36    filter.validate()?;
37
38    println!("{}", filter.dump());
39
40    if let Some(codec) = encoder.codec()
41        && !codec
42            .capabilities()
43            .contains(ffmpeg::codec::capabilities::Capabilities::VARIABLE_FRAME_SIZE)
44    {
45        filter
46            .get("out")
47            .unwrap()
48            .sink()
49            .set_frame_size(encoder.frame_size());
50    }
51
52    Ok(filter)
53}