Oral History File Specifications

Audio

Preservation File

• Wave PCM (WAV)
• Constant bit rate
• Sample rate as received, usually 44.1 kHz
• Bit depth as received, usually 16 bits
• Stereo channel layout

Access File

• MPEG Audio Layer 3 (MP3)
• Constant bit rate, at least 192 kb/s
• 44.1 kHz sample rate
• No bit depth setting, MP3 applies this dynamically based on bit rate
• Mono channel layout

Video

Preservation File

• ProRes 422 HQ (MOV)
• Resolution and frame rate as received
• Progressive (scan type/field order)
• 48 kHz audio sample rate
• 16 bit audio bit depth
• Stereo audio channel layout

Access File

• H.264 (MP4)
• Resolution and frame rate as received
• Progressive (scan type/field order)
• 4.5 Mbps target bitrate (Premiere will default to this for H.264)
• YUV 4:2:0 chroma subsampling (also Premiere default)
• 8 bit video bit depth (also Premiere default)
• AAC audio compression
• 48 kHz audio sample rate
• 192 kHz variable audio bitrate
• Stereo audio channel layout