As usual, the history of these files is a bit murky. It starts with the
initial commit. (At which some development had already been done,
according to the AUTHORS and ChangeLog files at the time, we should be
but covered with relicensing agreements, though.) then it goes on with
complete lack of modularization, which was cleaned up later (cd68e161).
As usual, we don't consider the copyright of the stuff that has been
moved out cleanly.
There were also contributions to generic code by people who could not be
reached or who did not agree to the relicensing, but this was all
removed.
The only patches that we could not relicense and which were still in the
current code in some form are from Dénes Balatoni: 422b0d2a, 32937181.
We could not reach him, so commits f34e1a0d and 18905298 remove his
additions. It still leaves the demux_control() declaration itself, but
we don't consider it copyrightable. It's basically an idiom that existed
in MPlayer before that change, applied to the demuxer struct. (We even
went as far as making sure to remove all DEMUXER_CTRLs the original
author added.)
Commit be54f481 might be a bit of a corner case, but this was rewritten,
and we consider the old copyright removed long ago.
Similar purpose as f34e1a0dee.
Somehow this is much more natural too, and needs less code.
This breaks runtime updates to duration. This could easily be fixed, but
no important demuxer does this anyway. Only demux_raw and demux_disc
might (the latter for BD/DVD). For the latter it might actually have
some importance when changing titles at runtime (I guess?), but guess
what, I don't care.
This is more uniform, and potentially gets rid of some past copyrights.
It might be that this subtly changes caching behavior (it seems before
this, it synced to the demuxer if the length was unknown, which is not
what we want.)
MaxCLL is the more authoritative source for the metadata we are
interested in. The use of mastering metadata is sort of a hack anyway,
since there's no clearly-defined relationship between the mastering peak
brightness and the actual content. (Unlike MaxCLL, which is an explicit
relationship)
Also move the parameter fixing to `fix_image_params`
I don't know if the avutil check is strictly necessary but I've included
it anyway to be on the safe side.
List of changes:
1. Kill nom_peak, since it's a pointless non-field that stores nothing
of value and is _always_ derived from ref_white anyway.
2. Kill ref_white/--target-brightness, because the only case it really
existed for (PQ) actually doesn't need to be this general: According
to ITU-R BT.2100, PQ *always* assumes a reference monitor with a
white point of 100 cd/m².
3. Improve documentation and comments surrounding this stuff.
4. Clean up some of the code in general. Move stuff where it belongs.
This file is an leftover from when img_format.h was changed from using
the ancient FourCCs (based on Microsoft multimedia conventions) for
pixel formats to a simple enum. The remaining cases still inherently
used FourCCs for whatever reasons.
Instead of worrying about residual copyrights in this file, just move it
into code we don't want to relicense (the ancient Linux TV code). We
have to fix some other code depending on it. For the most part, we just
replace the MP_FOURCC macro with libavutil's MKTAG (although the macro
definition is exactly the same). In demux_raw, we drop some pre-defined
FourCCs, but it's not like it matters. (Instead of
--demuxer-rawvideo-format use --demuxer-rawvideo-mp-format.)
Since this demuxer is based on code by michael, this file can become
LGPL only once the mpv core becomes LGPL, and this is preparation for
it.
There were quite a lot of changes for rearranging preferred libavformat
vs. internal MPlayer demuxers, codec mappings, and filename extensions,
but all this got removed, so some of the relevant authors weren't asked.
cehoyos, who disagreed with LGPL, made a few changes in the past (mostly
codec mapping and deinterlacing related things), but all of them were
removed, mostly due to libavformat API cleanups.
adland, who could not be reached, did commit 057916ee65, but it's easy
to essentially revert the change (this is what the source changes in
this commit do), so we don't need to think about it.
Chris Welton, who could not be reached, made a simple change in commit
958c41d9b6. Fortunately, the API changed again, and his changes were
removed, so we don't need to think about this either.
There is an anonymous contribution in commit 085f35f4b4 - since this
did not introduce any original code, and the probe code was heavily
rewritten multiple times, I don't consider it relevant.
This switches back the --demuxer-lavf-probe-info default for HLS from
"no" to "yes".
Apparently the old default caused problems with the FFmpeg MediaCodec
wrapper. I'm not sure whether it's due to the extradata (which would not
make any sense as MediaCodec takes in Annex B formatted h264 data), or
something else. Reportedly, enabling probing fixes it though, so enable
it again.
Add disparaging comment about Google software/APIs here.
This affects in particular the heuristic that enables byte seeks in some
cases with .ts input. --demuxer-lavf-hacks=no should disable this
behavior now.
In the previous commit, I claimed that this GUID stuff was a libavformat
extension, but that seems to be completely wrong. (LATM might be an
extension of some kind, though.)
I don't know what Microsoft calls this GUID "suffix" though. It's
generally used to wrap wav format tags and video FourCCs as GUIDs.
I guess you could grep Microsoft headers for it to find its name,
or something.
Indeed, FFmpeg found a way to maximize the misery around VfW/AVI-style
muxing. It appears it can mux a number of random codecs by using random
format tags. To make this even more stranger, it has a probably custom
GUID for signaling them, although for unknown reasons this is done only
"sometimes" (judging from FFmpeg's riffenc.c).
Whatever, it's not too hard to support it. Also apparently fix the
incorrect interpretation of extended formats - there's absolutely no
reason to assume they're always PCM. Instead, check for the correct
GUIDs. Also while we're at it, move the channel mask handling also to
codec_tag.c, so all WAVEFORMATEXTENSIBLE handling is in one place. (With
the normal wav header handling strangely still in demux_mkv.c.)
The case I was looking at (aac_latm muxing) decodes now. While I'm not
entirely sure about its correctness (libavformat has a weird
special-case for SBR), it certainly doesn't try to play it as PCM,
which is much of an improvement.
The extradata mess in the demux_mkv.c A_MS/ACM code path is unfortunate
and ugly, but has less impact than refactoring all the code to make
this specific case nicer.
Did I mention yet that I hate VfW-style mkv muxing?
Try to read header elements stored at the end of the file in the order
of their position. (It would be nicer if mkv simply told us a range of
elements to parse, but it doesn't do that.)
This can potentially reduce seek elements, although I didn't check if
any real files trigger this. The real contribution by this change is
that it does not defer reading the CUE index if we need to seek to the
end of the file anyway. This can actually avoid 2 seeks when opening a
file and --start is used, and the file has other headers elements at the
end of the file (like tags).
All authors of the current code have agreed.
For most of its life, MPlayer used Microsoft structs like WAVEFORMATEX
to describe media content. It appears these were copied from wine in
61c5a99851. Copyright is unclear, but mpv completely removed use of
these structs anyway. (demux_mkv.c still contains code to read these
fields from a byte stream, but the struct is fully gone.)
42f97b2b82: cehoyos (who probably didn't agree with LGPL) applied a
patch by someone who agreed. It's unknown whether cehoyos modified the
patch (and thus his copyright would apply), but the changed code was
removed anyway. (The code was first moved somewhere else, then removed.)
efd53eed61: the patch author was not asked. Although the mkv_sh_sub_t
struct was later moved to stheader.h, the added field was removed
without replacement.
f6878753fb: nick, who could not be reached, added an include guard, but
the guard was changed several times later, and it's probably not
copyrightable anyway.
afb0fd5ea1: the same nick adds a field that was later replaced and
finally removed again in 8cd6b20571.
All contributors have agreed. In 3a43f13fce, someone who potentially
disagreed reverted a commit by someone else (restoring the original
state). This shouldn't matter for Copyright, and all of the affected
code was rewritten/removed anyway.
Most contributors have agreed. This claims it's based on gstreamer code,
but this was LGPL at the time (and still is). Contributors whose code
was removed were not accounted for. There are still some potentially
problematic cases:
06eee1b67 is potentially the most problematic case. Most of these
changes are gone due to mpv not using BITMAPINFOHEADER anymore. Some
of the other changes are rather trivial. If someone contests this and
claims that copyrightable changes are left, the original change can
simply be reverted.
62bfae140 has only 2 lines left: a "char *name;" struct field, and a
line that prints a message. All other code was removed. The parsing code
in particular was made declarative, which replaced reading this element
explicitly (and other elements, see 1b22101c77). I'm putting the log
message under HAVE_GPL, but I don't think the declaration is
copyrightable, or the mere concept of reading this element. Redoing the
other 2 lines of code would result in the same program text.
d41e860ba was applied by someone who (potentially) disagreed. The patch
itself is from someone who did agree, though. It's unknown whether the
applier changed the patch. But it seems unlikely, and the change was
mostly rewritten.
50a86fcc3 all demux_mkv changes were reverted (old stdout slave mode)
3a406e94d same
2e40bfa13 the old MPlayer subtitle code was completely removed
316bb1d44 completely removed in 1cf4802c1d87f93d9d7 same
11bfc6780 relative seeks were removed in 92ba630796be54f4813 the corresponding demux_mkv code was removed in 5dabaaf093efd53eed6 all internal vobsub handling is now in FFmpeg
d7f693a20 removed in f3db4b0b93e8a1b3713 removed in 522ee6b783cfb890259 removed, see 6b1374b203 for analysis
c80808b5a same
It's all explained in the DOCS changes. Although this option was always
kind of obscure and pointless. Until it is removed, the only reason for
setting it would be to raise the static default limit, so change its
default to INT_MAX so that it does nothing by default.
Apparently fixes youtube mp4 streams if avformat_find_stream_info() is
not called.
Keeping audio/video track and other track durations separate is for
the sake of embedded subtitle streams, where we want to include the
duration of overlong subtitle streams (I think).
Includes hls, mp4, mkv by default. This also avoids stupid things like
decoding at least 1 video frame per stream in the demuxer.
This also add --demuxer-lavf-probe-info to give finer control over what
happens.
We use the metadata provided by youtube-dl to sort-of implement
fragmented DASH streaming.
This is all a bit hacky, but hopefully a makeshift solution until
libavformat has proper mechanisms. (Although in danger of being one
of those temporary hacks that become permanent.)
Instead of enabling it only when a stream-cache is enabled, also try to
enable it independently from that if the demuxer is marked as
is_network.
Also add some code to the EDL code, so EDLs containing network streams
are automatically cached this way.
Extend the OSD info line so that it shows the demuxer cache in this case
(more or less).
I didn't find where or whether options.rst describes how the demuxer
cache is enabled, so no changes there.
Because it's kind of dumb. (But not sure if it was worth the trouble.)
For stream_file.c, we add new explicit fields. The rest are rather
special uses and can be killed by comparing the stream impl. name.
The changes to DVD/BD/CD/TV are entirely untested.
"uncached_stream" is a pretty bad name. It could be mistaken for a
boolean, and then its meaning would be inverted. Rename it.
Also add a "caching" field, which signals that the stream is a cache or
reads from a cache. This is easier to understand and more flexible.
This could potentially have caused fun crashes if the --tv-channels
option was used, and something more advanced than tv:// was used to open
it. (This code is still untested.)
Fixes seeking with:
https://bugs.chromium.org/p/chromium/issues/detail?id=497889
Haali also ignores the element's contents, and interprets its presence
as the block not being a keyframe. FFmpeg is going to have an equivalent
change.
I don't know yet whether the affected sample is valid - a reference
timestamp of 0 doesn't make too much sense to me.
Some files appear to use them. In the sample I've seen, one field was
"Performer" instead of "PERFORMER".
This change is slightly risky, because it increases the chance of
misdetecting other formats as cue files.
Fixes#4057.
The FFmpeg versions we support all have the APIs we were checking for.
Only Libav missed them. Simplify this by explicitly checking for FFmpeg
in the code, instead of trying to detect the presence of the API.
This was excessively useless, and I want my time back that was needed to
explain users why they don't want to use it.
It captured the byte stream only, and even for types of streams it was
designed for (like transport streams), it was rather questionable.
As part of the removal, un-inline demux_run_on_thread() (which has only
1 call-site now), and sort of reimplement --stream-dump to write the
data directly instead of using the removed capture code.
(--stream-dump is also very useless, and I struggled coming up with an
explanation for it in the manpage.)
Disabling cache readahead by default until at least 1 track is selected
is mainly for external files and such, where you don't want them to use
up resources until they're actually used.
It doesn't make sense to disable the cache for the demuxer opened for
prefetch. Also, it's fine to let it do that for the main file too (doing
or not doing it is of little consequence). That saves us from having to
distinguish them.
Cover art handling is a disgusting hack that causes a mess in all
components. And this will stay this way. This is the Xth time I've
changed cover art handling, and that will probably also continue.
But change the code such that cover art is injected into the demux
packet stream, instead of having an explicit special case it in the
decoder glue code. (This is somewhat more similar to the cover art hack
in libavformat.)
To avoid that the over art picture is decoded again on each seek, we
need some additional "caching" in player/video.c. Decoding it after each
seek would work as well, but since cover art pictures can be pretty
huge, it's probably ok to invest some lines of code into caching it.
One weird thing is that the cover art packet will remain queued after
seeks, but that is probably not an issue.
In exchange, we can drop the dec_video.c code, which is pretty
convenient for one of the following commits. This code duplicates a
bunch of lower-level decode calls and does icky messing with this weird
state stuff, so I'm glad it goes away.
It has only 1 caller, and is too far appart within the file. I think it
used to have multiple callers, but now it just doesn't make any sense to
keep it separate anymore.
This was probably the intention all along. But I honestly have no idea
what this code even does.
Due to what ebml_read_vlen_int() is used for, this is unlikely to have
mattered anyway as it rarely/never reads huge values. Which is probably
why this has worked for over a decade.
TrueHD is a fucked up audio codec with extremely small frame sizes. Some
of these frames start with full headers, which are usually marked as
keyframes, and from which decoding can be started (or at least that's
what you'd expect).
So for such tracks we should probably trust the keyframe flags. Doesn't
really improve seek behavior, though.
Some files have audio tracks with packets that do not have a keyframe
flag set at all. I don't think there's any audio codec which actually
needs keyframe flags, so always assume an audio packet is a keyframe
(which, in Matroska terminology, means it can start decoding from that
packet).
The file in question had these set:
| + Multiplexing application: Lavf57.56.100 at 313
| + Writing application: Lavf57.56.100 at 329
Garbage produced by garbage...
There are other such files produced by mkvmerge, though. It's not
perfectly sure whether these have been produced by FFmpeg as well
(mkvmerge often trusts the information in the source file, even if it's
wrong - so other samples could have been remuxed from FFmpeg).
Fixes#3920.
