[FFmpeg-devel] [PATCH] avfilter/image2: Add source file path and basename to each packet side data.
Alexandre Heitor Schmidt
alexandre.schmidt at gmail.com
Sat Dec 21 17:46:10 EET 2019
On 19/12/2019 16:46, Michael Niedermayer wrote:
> On Tue, Dec 17, 2019 at 02:30:39PM +0000, Alexandre Heitor Schmidt wrote:
>> On 17/12/2019 00:35, Marton Balint wrote:
>>> On Mon, 16 Dec 2019, Alexandre Heitor Schmidt wrote:
>>>> This is the second time I'm submiting this patch, now modified to be
>>>> less intrusive, as sugested by Marton Balint, and hopefully
without git
>>>> send-email messing up with the diff by replacing '@' within
>>>> documentation entries.
>>>>
>>>> The patch modifies image2 filter to make available two special
metadata
>>>> entries called source_path and source_file, which represents,
>>>> respectively, the complete path to the source image for the current
>>>> frame and the basename i.e. the file name related to the current
frame.
>>>> These can then be used by filters like drawtext and others.
>>>>
>>>> doc/filters: The documentation for drawtext was also updated and
an usage
>>>> example was added.
>>>>
>>>> Fixes #2874.
>>>>
>>>> Signed-off-by: Alexandre Heitor Schmidt <alexandre.schmidt at gmail.com>
>>>> ---
>>>> doc/filters.texi | 15 +++++++++++++--
>>>> libavformat/img2.h | 2 ++
>>>> libavformat/img2dec.c | 28 ++++++++++++++++++++++++++++
>>>> 3 files changed, 43 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/doc/filters.texi b/doc/filters.texi
>>>> index c543203ce3..15498aee0d 100644
>>>> --- a/doc/filters.texi
>>>> +++ b/doc/filters.texi
>>>> @@ -9723,8 +9723,12 @@ Available metadata can be identified by
inspecting
>> entries
>>>> starting with TAG included within each frame section
>>>> printed by running @code{ffprobe -show_frames}.
>>>>
>>>> -String metadata generated in filters leading to
>>>> -the drawtext filter are also available.
>>>> +String metadata generated in filters leading to the drawtext
filter are
>> also
>>>> +available. For example, image2 filter generates two special metadata
>> fields
>>>> +called @var{source_path} and @var{source_basename} for each input
frame
>>>> +generated from a single image. @var{source_path} contains the entire
>> path
>>>> +to input filename, while @var{source_basename} contains the
equivalent
>>>> +to @code{basename(source_path)}.
>>>
>>> This does not really belong here, you are documenting the image2
>> *demuxer*'s behaviour of setting source_basename and source_path
metadata
>> fields.
>>
>> Ok. Fixed that. Updated the example for drawtext and added the
metadata tags
>> to demuxers.texi
>>
>>> The only thing that might be relevant here is that the metadata can not
>>> only come from filters but from demuxers as well.
>>>
>>> Also since the metadata names are demuxer specific probably it is
better
>> to use hierarchical names, like "lavf.image2dec.source_path" and
>> "lavf.image2dec.source_basename", similar to how the filters set their
>> custom metadata fields.
>>
>> Right. Names of metadata tags changed accordingly.
>>
>>>> @item n, frame_num
>>>> The frame number, starting from 0.
>>>> @@ -9872,6 +9876,13 @@
>>
drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
>>>>
>>
drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a
>>>> @end example
>>>>
>>>> + at item
>>>> +Plot special @var{source_basename} metadata, extracted from each
input
>> frame, or
>>>> +the string "NA" if the metadata is not defined.
>>>> + at example
>>>>
+drawtext="fontsize=20:fontcolor=white:fontfile=FreeSans.ttf:text='%{metadata\:source_basename\:NA}':x=10:y=10"
>>>> + at end example
>>>> +
>>>
>>> The example can stay as is, that is fine.
>>
>> Ok. I just updated the metadata tag names.
>>
>>>> @end itemize
>>>>
>>>> For more information about libfreetype, check:
>>>> diff --git a/libavformat/img2.h b/libavformat/img2.h
>>>> index 0e5b374a6b..8208c1f58b 100644
>>>> --- a/libavformat/img2.h
>>>> +++ b/libavformat/img2.h
>>>> @@ -74,5 +74,7 @@ extern const AVOption ff_img_options[];
>>>>
>>>> int ff_img_read_header(AVFormatContext *s1);
>>>>
>>>> +int add_filename_as_pkt_side_data(char *filename, AVPacket *pkt);
>>>> +
>>>
>>> No need to make it part of the header.
>>
>> Removed.
>>
>>>> int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt);
>>>> #endif
>>>> diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
>>>> index f8b4a655a5..3fb7aa7967 100644
>>>> --- a/libavformat/img2dec.c
>>>> +++ b/libavformat/img2dec.c
>>>> @@ -374,6 +374,32 @@ int ff_img_read_header(AVFormatContext *s1)
>>>> return 0;
>>>> }
>>>>
>>>> +/**
>>>> + * Add this frame's source path and basename to packet's sidedata
>>>> + * as a dictionary, so it can be used by filters like 'drawtext'.
>>>> + */
>>>> +int add_filename_as_pkt_side_data(char *filename, AVPacket *pkt) {
>>>
>>> This can be made static.
>>
>> Done.
>>
>>>> + uint8_t* metadata;
>>>> + int metadata_len;
>>>> + AVDictionary *d = NULL;
>>>> + char *packed_metadata = NULL;
>>>> +
>>>> + av_dict_set(&d, "source_path", filename, 0);
>>>> + av_dict_set(&d, "source_basename", av_basename(filename), 0);
>>>> +
>>>> + packed_metadata = av_packet_pack_dictionary(d, &metadata_len);
>>>> + if (!packed_metadata)
>>>> + return AVERROR(ENOMEM);
>>>> + if (!(metadata = av_packet_new_side_data(pkt,
>> AV_PKT_DATA_STRINGS_METADATA, metadata_len))) {
>>>> + av_freep(&packed_metadata);
>>>> + return AVERROR(ENOMEM);
>>>> + }
>>>> + memcpy(metadata, packed_metadata, metadata_len);
>>>> + av_freep(&packed_metadata);
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt)
>>>> {
>>>> VideoDemuxData *s = s1->priv_data;
>>>> @@ -485,6 +511,8 @@ int ff_img_read_packet(AVFormatContext *s1,
AVPacket
>> *pkt)
>>>>
>>>> if (s->is_pipe)
>>>> pkt->pos = avio_tell(f[0]);
>>>> + else if ( (res = add_filename_as_pkt_side_data(filename,
pkt)) != 0
>> )
>>>> + goto fail;
>>>
>>> Cosmetics/nitpicking, a separate if and the usual way of checking for
>> errors is more readable IMHO:
>>>
>>> if (!s->is_pipe) {
>>> res = add_filename_as_pkt_side_data(filename, pkt);
>>> if (res < 0)
>>> goto fail;
>>> }
>>
>> Rewritten.
>>
>>> Thanks,
>>> Marton
>>
>> Thank YOU for the awesome support!
>>
>> New patch file attached.
>>
>> Alex.
>>
>>
>>
>
>> doc/demuxers.texi | 11 +++++++++++
>> doc/filters.texi | 7 +++++++
>> libavformat/img2dec.c | 32 ++++++++++++++++++++++++++++++++
>> 3 files changed, 50 insertions(+)
>> 62f78a0d6b40d6338759738e44c8decadad2d0a4
0001-avformat-image2-Metadata-identifying-the-source-path.patch
>> From 7177c9c55f0f38ccdd6b7845f8027ee454766d11 Mon Sep 17 00:00:00 2001
>> From: Alexandre Heitor Schmidt <alexandre.schmidt at gmail.com>
>> Date: Tue, 17 Dec 2019 12:31:41 +0000
>> Subject: [PATCH] avformat/image2: Metadata identifying the source
path of
>> input filename and documentation for its usage.
>>
>> libavformat/img2dec.c: Modify image2 demuxer to make available
>> two special metadata entries called lavf.image2dec.source_basename
>> and lavf.image2dec.source_basename, which represents, respectively,
>> the complete path to the source image for the current frame and
>> the basename i.e. the file name related to the current frame.
>> These can then be used by filters like drawtext and others.
>>
>> doc/demuxers.texti: Documented the two special metadata tags.
>>
>> doc/filters.texti: Added an usage example for these tags.
>>
>> Fixes #2874.
>>
>> Signed-off-by: Alexandre Heitor Schmidt <alexandre.schmidt at gmail.com>
>> ---
>> doc/demuxers.texi | 11 +++++++++++
>> doc/filters.texi | 7 +++++++
>> libavformat/img2dec.c | 32 ++++++++++++++++++++++++++++++++
>> 3 files changed, 50 insertions(+)
>>
>> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
>> index 0d13bdd1b3..96cff22267 100644
>> --- a/doc/demuxers.texi
>> +++ b/doc/demuxers.texi
>> @@ -362,6 +362,17 @@ determine the format of the images contained in
the files.
>> The size, the pixel format, and the format of each image must be the
>> same for all the files in the sequence.
>>
>> +Along with the metadata found within each file, two special metadata
>> +fields are made available for other filters (see @var{drawtext} filter
>> +for examples):
>> +
>> + at table @option
>> + at item lavf.image2dec.source_path
>> +Corresponds to the full path to the input image being read.
>> + at item lavf.image2dec.source_basename
>> +Corresponds to the name of the file being read.
>> + at end table
>> +
>> This demuxer accepts the following options:
>> @table @option
>> @item framerate
>> diff --git a/doc/filters.texi b/doc/filters.texi
>> index 527c6a08b2..ec0d4bd4a2 100644
>> --- a/doc/filters.texi
>> +++ b/doc/filters.texi
>> @@ -9872,6 +9872,13 @@
drawtext=fontfile=FreeSans.ttf:text=DOG:fontsize=24:x=10:y=20+24-max_glyph_a,
>>
drawtext=fontfile=FreeSans.ttf:text=cow:fontsize=24:x=80:y=20+24-max_glyph_a
>> @end example
>>
>> + at item
>> +Plot special @var{lavf.image2dec.source_basename} metadata onto
each frame if
>> +such metadata exists. Otherwise, plot the string "NA".
>> + at example
>>
+drawtext="fontsize=20:fontcolor=white:fontfile=FreeSans.ttf:text='%{metadata\:lavf.image2dec.source_basename\:NA}':x=10:y=10"
>> + at end example
>> +
>> @end itemize
>>
>> For more information about libfreetype, check:
>
> make
> HTML doc/ffmpeg-all.html
> doc/filters.texi:9879: misplaced {
> doc/filters.texi:9879: misplaced }
> make: *** [doc/ffmpeg-all.html] Error 1
>
>
> [...]
Michael, would you mind sharing your ./configure and make lines, so I
can try to reproduce your environment here and thus avoid sending
non-working patches?
Thank you!
Alex.
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