Video and Audio Media Formats

A media format is a manufacturers specification of how to combine multiple streams of media encoded with specific parameters of a specific media codec into a specific media container.

AVC Intra 100

AVC-I 100 format files are either MXF or MOV files containing one stream of i-frame only [H.264 video] and zero or more streams of PCM audio.

Minimal example of encoding with FFmpeg:

ffmpeg  \
 -i <INPUT> \
 -filter:v "
   scale=1920:1080:interl=1,
   format=yuv422p10le,
   setparams=field_mode=tff:range=tv:color_primaries=bt709:color_trc=bt709:colorspace=bt709,
   setdar=dar=16/9" \
 -codec:v libx264 \
 -vb 100M \
 -g 1 \
 -tune psnr \
 -avcintra-class 100 \
 -flags +ilme+ildct \
 -codec:a pcm_s24le \
 -ar 48000 \
 -vtag ai12 \
 <OUTPUT>

• scale=1920:1080:interl=1,format=yuv422p10le is equivalent to -pix_fmt yuv422p10le but works with interlaced media
• setparams=field_mode=tff is equivalent to -top 1
• setparams=range=tv is equivalent to -color_range 2
• setparams=color_primaries=bt709 is equivalent to -color_primaries bt709
• setparams=color_trc=bt709 is equivalent to -color_trc bt709
• setparams=colorspace=bt709 is equivalent to -colorspace bt709

IMX

IMX30, IMX40 and IMX50 are tightly defined MXF files containing one stream of MPEG 2 video and one stream of PCM audio carrying four channels of audio.

• IMX50 was the BBC’s standard definition broadcast format of choice.
• IMX30 was BBC News’ standard definition broadcast format of choice.

IMX30

Minimal example of encoding with FFmpeg: assumes input media is 720 pixels wide by 608 pixels high, with 32 lines of VBI at the top of the video:

ffmpeg -i <INPUT_FILE_720x608>
 -codec:v  mpeg2video \
 -b:v 30000k \
 -minrate 30000k \
 -maxrate 30000k \
 -bufsize 1200000 \
 -rc_init_occupancy 1200000 \
 -intra \
 -flags +ildct+low_delay \
 -intra_vlc 1 \
 -non_linear_quant 1 \
 -ps 1 \
 -qmin 1 \
 -qmax 3 \
 -dc 10 \
 -g 1 \
 -qscale 1
 -rc_max_vbv_use 1 \
 -rc_min_vbv_use 1 \
 -codec:a pcm_s16le \
 -ar 48000 \
 -ac 4\
 -color_range tv \
 -colorspace bt470bg \
 -color_primaries bt470bg \
 -color_trc gamma28 \
 -top 1 \
 -f mxf_d10
 <OUTPUT.MXF>

XAVC

Sony use the term XAVC to describe a variety of media formats.

• XAVC - H.264 compressed video and PCM audio in an MXF file container
  • XAVC-I - I-frame only video encoding, very high bitrate, and usually very high quality
  • XAVC-L - Long-GOP video encoding, lower bitrate and harder for software to decode
• XAVC H - H.265 compressed video and PCM audio in an MXF file container
• XAVC S - Semi-pro H.264 compressed video and PCM or AAC compressed audio in a MP4 file container
  • XAVC S-I - similar to XAVC-I
• XAVC HS - Semi-pro H.265 compressed video and PCM or AAC compressed audio in a MP4 file container

Full details of Sony’s web site