[FFmpeg-devel] [PATCH 2/2] lavf/mov: document the dvh1 codec switch based on hvcC availability

[Jan Ekström]

---
libavformat/mov.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index ec57a05803..497790522f 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1903,6 +1903,11 @@ static int mov_read_glbl(MOVContext *c, AVIOContext *pb, MOVAtom atom)
if (ret < 0)
return ret;
if (atom.type == MKTAG('h','v','c','C') && st->codecpar->codec_tag == MKTAG('d','v','h','1'))
+ /* HEVC-based Dolby Vision derived from hvc1.
+ Happens to match with an identifier
+ previously utilized for DV. Thus, if we have
+ the hvcC extradata box available as specified,
+ set codec to HEVC */
st->codecpar->codec_id = AV_CODEC_ID_HEVC;

return 0;

[Jan Ekström]

These are registered identifiers at the MPEG-4 RA, which are
defined as to be utilized for Dolby Vision AVC/HEVC streams that
are not correctly presentable by standards-compliant AVC/HEVC players.
According to the Dolby Vision specification for ISOBMFF, these sample
entry codes are specified to have the standard AVC or HEVC decoder
configuration box in addition to the Dolby custom DOVIConfigurationBox.
This is what enables us to decode the streams without custom parsing.
For correct presentation information from the DOVIConfigurationBox
is required (YCbCr or modified ICtCP, SDR or HDR, base or enhancement
layer).
---

Gentle Ping?

Jan

[Jan Ekström]

Post by Jan Ekström

These are registered identifiers at the MPEG-4 RA, which are
defined as to be utilized for Dolby Vision AVC/HEVC streams that
are not correctly presentable by standards-compliant AVC/HEVC players.
According to the Dolby Vision specification for ISOBMFF, these sample
entry codes are specified to have the standard AVC or HEVC decoder
configuration box in addition to the Dolby custom DOVIConfigurationBox.
This is what enables us to decode the streams without custom parsing.
For correct presentation information from the DOVIConfigurationBox
is required (YCbCr or modified ICtCP, SDR or HDR, base or enhancement
layer).
---

Gentle Ping?
Jan

Ping^2?

And if nobody really cares, I will reverse the comments on the AVC
entries (since I seem to have gotten them the wrong way around when
adding the comments and commit message late at night) and apply the
set tomorrow morning. These additional identifiers and the comment
should not be affecting existing FATE samples.

Best regards,
Jan

[Michael Niedermayer]

Post by Jan Ekström

Post by Jan Ekström

These are registered identifiers at the MPEG-4 RA, which are
defined as to be utilized for Dolby Vision AVC/HEVC streams that
are not correctly presentable by standards-compliant AVC/HEVC players.
According to the Dolby Vision specification for ISOBMFF, these sample
entry codes are specified to have the standard AVC or HEVC decoder
configuration box in addition to the Dolby custom DOVIConfigurationBox.
This is what enables us to decode the streams without custom parsing.
For correct presentation information from the DOVIConfigurationBox
is required (YCbCr or modified ICtCP, SDR or HDR, base or enhancement
layer).
---

Gentle Ping?
Jan

Ping^2?
And if nobody really cares, I will reverse the comments on the AVC
entries (since I seem to have gotten them the wrong way around when
adding the comments and commit message late at night) and apply the
set tomorrow morning. These additional identifiers and the comment
should not be affecting existing FATE samples.

probably ok, if tested and it works

thx

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