scuffle_mp4/boxes/types/
mp4a.rs

use std::io;

use bytes::{Buf, Bytes};

use super::btrt::Btrt;
use super::esds::Esds;
use super::stsd::{AudioSampleEntry, SampleEntry};
use crate::boxes::header::BoxHeader;
use crate::boxes::traits::BoxType;
use crate::boxes::DynBox;
use crate::codec::AudioCodec;

#[derive(Debug, Clone, PartialEq)]
/// AAC Audio Sample Entry
/// ISO/IEC 14496-14:2020(E) - 6.7
pub struct Mp4a {
    pub header: BoxHeader,
    pub audio_sample_entry: SampleEntry<AudioSampleEntry>,
    pub esds: Esds,
    pub btrt: Option<Btrt>,
    pub unknown: Vec<DynBox>,
}

impl Mp4a {
    pub fn new(audio_sample_entry: SampleEntry<AudioSampleEntry>, esds: Esds, btrt: Option<Btrt>) -> Self {
        Self {
            header: BoxHeader::new(Self::NAME),
            audio_sample_entry,
            esds,
            btrt,
            unknown: Vec::new(),
        }
    }

    #[allow(clippy::useless_asref)]
    pub fn codec(&self) -> io::Result<AudioCodec> {
        let info = self
            .esds
            .es_descriptor
            .decoder_config
            .as_ref()
            .and_then(|c| c.decoder_specific_info.as_ref().map(|c| c.data.clone()))
            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "Missing decoder specific info"))?;
        let aac_config = scuffle_aac::PartialAudioSpecificConfig::parse(&info)?;

        Ok(AudioCodec::Aac {
            object_type: aac_config.audio_object_type,
        })
    }
}

impl BoxType for Mp4a {
    const NAME: [u8; 4] = *b"mp4a";

    fn demux(header: BoxHeader, data: Bytes) -> io::Result<Self> {
        let mut reader = io::Cursor::new(data);

        let audio_sample_entry = SampleEntry::<AudioSampleEntry>::demux(&mut reader)?;
        let mut btrt = None;
        let mut esds = None;
        let mut unknown = Vec::new();

        while reader.has_remaining() {
            let dyn_box = DynBox::demux(&mut reader)?;
            match dyn_box {
                DynBox::Btrt(btrt_box) => {
                    btrt = Some(*btrt_box);
                }
                DynBox::Esds(esds_box) => {
                    esds = Some(*esds_box);
                }
                _ => {
                    unknown.push(dyn_box);
                }
            }
        }

        let esds = esds.ok_or_else(|| io::Error::new(io::ErrorKind::InvalidData, "Missing esds box"))?;

        Ok(Self {
            header,
            audio_sample_entry,
            esds,
            btrt,
            unknown,
        })
    }

    fn primitive_size(&self) -> u64 {
        self.audio_sample_entry.size()
            + self.btrt.as_ref().map(|b| b.size()).unwrap_or(0)
            + self.esds.size()
            + self.unknown.iter().map(|b| b.size()).sum::<u64>()
    }

    fn primitive_mux<T: io::Write>(&self, writer: &mut T) -> io::Result<()> {
        self.audio_sample_entry.mux(writer)?;
        self.esds.mux(writer)?;
        if let Some(btrt) = &self.btrt {
            btrt.mux(writer)?;
        }
        for unknown in &self.unknown {
            unknown.mux(writer)?;
        }
        Ok(())
    }
}
scuffle_mp4/boxes/types/mp4a.rs

scuffle_mp4/boxes/types/
mp4a.rs
