mp4-rust/src/mp4box/tfhd.rs

use byteorder::{BigEndian, WriteBytesExt};
use serde::Serialize;
use std::io::Write;

use crate::mp4box::*;

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Default)]
pub struct TfhdBox {
    pub version: u8,
    pub flags: u32,
    pub track_id: u32,
    pub base_data_offset: Option<u64>,
    pub sample_description_index: Option<u32>,
    pub default_sample_duration: Option<u32>,
    pub default_sample_size: Option<u32>,
    pub default_sample_flags: Option<u32>,
}

impl TfhdBox {
    pub const FLAG_BASE_DATA_OFFSET: u32 = 0x01;
    pub const FLAG_SAMPLE_DESCRIPTION_INDEX: u32 = 0x02;
    pub const FLAG_DEFAULT_SAMPLE_DURATION: u32 = 0x08;
    pub const FLAG_DEFAULT_SAMPLE_SIZE: u32 = 0x10;
    pub const FLAG_DEFAULT_SAMPLE_FLAGS: u32 = 0x20;
    pub const FLAG_DURATION_IS_EMPTY: u32 = 0x10000;
    pub const FLAG_DEFAULT_BASE_IS_MOOF: u32 = 0x20000;

    pub fn get_type(&self) -> BoxType {
        BoxType::TfhdBox
    }

    pub fn get_size(&self) -> u64 {
        let mut sum = HEADER_SIZE + HEADER_EXT_SIZE + 4;
        if TfhdBox::FLAG_BASE_DATA_OFFSET & self.flags > 0 {
            sum += 8;
        }
        if TfhdBox::FLAG_SAMPLE_DESCRIPTION_INDEX & self.flags > 0 {
            sum += 4;
        }
        if TfhdBox::FLAG_DEFAULT_SAMPLE_DURATION & self.flags > 0 {
            sum += 4;
        }
        if TfhdBox::FLAG_DEFAULT_SAMPLE_SIZE & self.flags > 0 {
            sum += 4;
        }
        if TfhdBox::FLAG_DEFAULT_SAMPLE_FLAGS & self.flags > 0 {
            sum += 4;
        }
        sum
    }
}

impl Mp4Box for TfhdBox {
    const TYPE: BoxType = BoxType::TfhdBox;

    fn box_size(&self) -> u64 {
        self.get_size()
    }

    fn to_json(&self) -> Result<String> {
        Ok(serde_json::to_string(&self).unwrap())
    }

    fn summary(&self) -> Result<String> {
        let s = format!("track_id={}", self.track_id);
        Ok(s)
    }
}

impl BlockReader for TfhdBox {
    fn read_block<'a>(reader: &mut impl Reader<'a>) -> Result<Self> {
        let (version, flags) = read_box_header_ext(reader);
        let track_id = reader.get_u32();

        let base_data_offset = if TfhdBox::FLAG_BASE_DATA_OFFSET & flags > 0 {
            Some(reader.get_u64())
        } else {
            None
        };

        let sample_description_index = if TfhdBox::FLAG_SAMPLE_DESCRIPTION_INDEX & flags > 0 {
            Some(reader.get_u32())
        } else {
            None
        };

        let default_sample_duration = if TfhdBox::FLAG_DEFAULT_SAMPLE_DURATION & flags > 0 {
            Some(reader.get_u32())
        } else {
            None
        };

        let default_sample_size = if TfhdBox::FLAG_DEFAULT_SAMPLE_SIZE & flags > 0 {
            Some(reader.get_u32())
        } else {
            None
        };

        let default_sample_flags = if TfhdBox::FLAG_DEFAULT_SAMPLE_FLAGS & flags > 0 {
            Some(reader.get_u32())
        } else {
            None
        };

        Ok(TfhdBox {
            version,
            flags,
            track_id,
            base_data_offset,
            sample_description_index,
            default_sample_duration,
            default_sample_size,
            default_sample_flags,
        })
    }

    fn size_hint() -> usize {
        8
    }
}

impl<W: Write> WriteBox<&mut W> for TfhdBox {
    fn write_box(&self, writer: &mut W) -> Result<u64> {
        let size = self.box_size();
        BoxHeader::new(Self::TYPE, size).write(writer)?;

        write_box_header_ext(writer, self.version, self.flags)?;
        writer.write_u32::<BigEndian>(self.track_id)?;
        if let Some(base_data_offset) = self.base_data_offset {
            writer.write_u64::<BigEndian>(base_data_offset)?;
        }
        if let Some(sample_description_index) = self.sample_description_index {
            writer.write_u32::<BigEndian>(sample_description_index)?;
        }
        if let Some(default_sample_duration) = self.default_sample_duration {
            writer.write_u32::<BigEndian>(default_sample_duration)?;
        }
        if let Some(default_sample_size) = self.default_sample_size {
            writer.write_u32::<BigEndian>(default_sample_size)?;
        }
        if let Some(default_sample_flags) = self.default_sample_flags {
            writer.write_u32::<BigEndian>(default_sample_flags)?;
        }

        Ok(size)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::mp4box::BoxHeader;

    #[test]
    fn test_tfhd() {
        let src_box = TfhdBox {
            version: 0,
            flags: 0,
            track_id: 1,
            base_data_offset: None,
            sample_description_index: None,
            default_sample_duration: None,
            default_sample_size: None,
            default_sample_flags: None,
        };
        let mut buf = Vec::new();
        src_box.write_box(&mut buf).unwrap();
        assert_eq!(buf.len(), src_box.box_size() as usize);

        let mut reader = buf.as_slice();
        let header = BoxHeader::read_sync(&mut reader).unwrap().unwrap();
        assert_eq!(header.kind, BoxType::TfhdBox);
        assert_eq!(src_box.box_size(), header.size);

        let dst_box = TfhdBox::read_block(&mut reader).unwrap();
        assert_eq!(src_box, dst_box);
    }

    #[test]
    fn test_tfhd_with_flags() {
        let src_box = TfhdBox {
            version: 0,
            flags: TfhdBox::FLAG_SAMPLE_DESCRIPTION_INDEX
                | TfhdBox::FLAG_DEFAULT_SAMPLE_DURATION
                | TfhdBox::FLAG_DEFAULT_SAMPLE_FLAGS,
            track_id: 1,
            base_data_offset: None,
            sample_description_index: Some(1),
            default_sample_duration: Some(512),
            default_sample_size: None,
            default_sample_flags: Some(0x1010000),
        };
        let mut buf = Vec::new();
        src_box.write_box(&mut buf).unwrap();
        assert_eq!(buf.len(), src_box.box_size() as usize);

        let mut reader = buf.as_slice();
        let header = BoxHeader::read_sync(&mut reader).unwrap().unwrap();
        assert_eq!(header.kind, BoxType::TfhdBox);
        assert_eq!(src_box.box_size(), header.size);

        let dst_box = TfhdBox::read_block(&mut reader).unwrap();
        assert_eq!(src_box, dst_box);
    }
}