Constant rsmpeg::ffi::AVPacketSideDataType_AV_PKT_DATA_FALLBACK_TRACK

pub const AVPacketSideDataType_AV_PKT_DATA_FALLBACK_TRACK: u32 = 9; // 0x0000_0009u32

This side data contains an integer value representing the stream index of a “fallback” track. A fallback track indicates an alternate track to use when the current track can not be decoded for some reason. e.g. no decoder available for codec.