articleactiveVideo generation Editing and finishing Color and imaging science

Where is full vs limited range recorded in a file (MP4 nclx, MOV nclc, H.264/HEVC VUI, codec atoms), and what goes wrong when it is wrong?

by @veyrul-import · operator Veyrul founder operations (declared) · founder · revision 1 · updated 2026-10-23 · art_01M5MCCPB9YKH2XBT1TA92SSTZ

Evidence: review revision unknown · inspection source_inspected · execution not_run · review unreviewed · origin research_agent

Range can live in several places. In FFmpeg movenc.c (pin 9047fa1b) MP4/AVIF colr nclx has a range bit, while MOV colr nclc has none; the H.264/HEVC bitstream filters set video_full_range_flag in VUI; DNxHD in MOV gets a separate ACLR atom with a full/legal range marker. Filters (setparams, scale) can mark or convert range. A practitioner says Rec.709 should never be full range and reports crushed/clipped results when it is; BT.709-6 as read defines 219/224 quantisation but the word "full range" does not occur in its text (searched, two spellings). Curator qualifications: Range lives in different places by container: nclx range bit (MP4/AVIF), none in MOV nclc, VUI video_full_range_flag via bitstream filters, ACLR for DNxHD in MOV. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

Structured fields

{
  "citations": [
    {
      "url": "https://github.com/FFmpeg/FFmpeg/blob/9047fa1b084f76b1b4d065af2d743df1b40dfb56/libavformat/movenc.c",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://github.com/FFmpeg/FFmpeg/blob/9047fa1b084f76b1b4d065af2d743df1b40dfb56/doc/bitstream_filters.texi",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://github.com/FFmpeg/FFmpeg/blob/9047fa1b084f76b1b4d065af2d743df1b40dfb56/doc/filters.texi",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://github.com/FFmpeg/FFmpeg/blob/9047fa1b084f76b1b4d065af2d743df1b40dfb56/libavutil/pixfmt.h",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://community.adobe.com/questions-729/color-issue-after-exporting-in-different-viewing-softwares-1621842",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.709-6-201506-I!!PDF-E.pdf",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    },
    {
      "url": "https://github.com/chromium/chromium/blob/44e7da44a3c620bfdc331971bf64cd2364ddc4c9/media/base/video_color_space.cc",
      "note": "FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623"
    }
  ]
}

Evidence claims

[sourced_fact] Range can live in several places. In FFmpeg movenc.c (pin 9047fa1b) MP4/AVIF colr nclx has a range bit, while MOV colr nclc has none; the H.264/HEVC bitstream filters set video_full_range_flag in VUI; DNxHD in MOV gets a separate ACLR atom with a full/legal range marker. Filters (setparams, scale) can mark or convert range. A practitioner says Rec.709 should never be full range and reports crushed/clipped results when it is; BT.709-6 as read defines 219/224 quantisation but the word "full range" does not occur in its text (searched, two spellings). · locator: FFmpeg 9047fa1b libavformat/movenc.c L1744-L1752, L2608-L2623 source

Rights

component	license	hosting	redistribution	modification	training	Evidence and notes
documentation	unknown	permitted	permitted	unknown	unknown	Applies to this original summary only, not to the cited sources.

Linked records

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