| Message ID | 20200511143159.19390-1-david@andreoletti.net |
|---|---|
| State | New |
| Delegated to: | Michael Niedermayer |
| Headers | show |
| Series | [FFmpeg-devel] drawtext: Allow textfile path to be expanded per frame | expand |
| Context | Check | Description |
|---|---|---|
| andriy/default | pending | |
| andriy/make | success | Make finished |
| andriy/make_fate | success | Make fate finished |
Hi ffmpeg maintainers / community,
New contributor here. The patch [0] for the drawtext filter was submitted some
time ago now but has been reviewed yet. It seems there is no official maintainer
for this filter (as per the MAINTAINERS file)
What should be done to have it reviewed ?
[0]
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/
Regards,
David Andreoletti
On Mon, May 11, 2020 2:31 PM, David Andreoletti david@andreoletti.net wrote:
drawtext allows a file to be reloaded per frame. However,
the file to be reloaded is constant across frame. With
textfile now supporting text expansion, a different file can
be reloaded per frame. Eg: textfile=/path/fo/file{frame_num}.txt
Signed-off-by: David Andreoletti <david@andreoletti.net>
---
doc/filters.texi | 16 +++++++++++++---
libavfilter/vf_drawtext.c | 19 ++++++++++++++++---
2 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index d19fd346ae..460d65dd88 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9659,13 +9659,13 @@ The default value of @var{borderw} is 0.
Set the color to be used for drawing border around text. For the syntax of
this
option, check the @ref{color syntax,,"Color" section in the ffmpeg-utils
manual,ffmpeg-utils}.
The default value of @var{bordercolor} is "black".
@item expansion
-Select how the @var{text} is expanded. Can be either @code{none},
+Select how the @var{text} and @var{textfile} are expanded. Can be either
@code{none},
@code{strftime} (deprecated) or
@code{normal} (default). See the @ref{drawtext_expansion, Text expansion}
section
below for details.
@item basetime
Set a start time for the count. Value is in microseconds. Only applied
@@ -9786,15 +9786,19 @@ of UTF-8 encoded characters.
This parameter is mandatory if no text string is specified with the
parameter @var{text}.
If both @var{text} and @var{textfile} are specified, an error is thrown.
+This parameter supports (per frame) variable expansion. Per frame variable
+expansion requires @code{reload=1}. See @var{expansion} for details.
+
+
@item reload
-If set to 1, the @var{textfile} will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
+If set to 1, then before each frame, @var{textfile} file path will be expanded
and then the file at said path will be reloaded.
+Be sure to update the file atomically, or it may be read partially, or even
fail.
@item x
@item y
The expressions which specify the offsets where text will be drawn
within the video frame. They are relative to the top/left border of the
output image.
@@ -10060,12 +10064,18 @@
drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
@item
Show the content of file @file{CREDITS} off the bottom of the frame and scroll
up.
@example
drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
@end example
+@item
+Each frame, reload a different text file at /path/to/frameX.txt, where X is
replaced with the frame number being processed by the filter
+@example
+drawtext="expansion:normal:textfile=/path/to/frame%@{frame_num@}.txt:reload=1"
+@end example
+
@item
Draw a single green letter "g", at the center of the input video.
The glyph baseline is placed at half screen height.
@example
drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
@end example
diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index abe1ca6c35..ffb1ff2330 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -152,13 +152,14 @@ typedef struct DrawTextContext {
AVBPrint expanded_text; ///< used to contain the expanded text
uint8_t *fontcolor_expr; ///< fontcolor expression to evaluate
AVBPrint expanded_fontcolor; ///< used to contain the expanded fontcolor spec
int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
FT_Vector *positions; ///< positions for each element in the text
size_t nb_positions; ///< number of elements of positions array
- char *textfile; ///< file with text to be drawn
+ char *textfile; ///< filename with text to be drawn
+ AVBPrint expanded_textfile; ///< Same as textfile, except the filename can be
expanded
int x; ///< x position to start drawing text
int y; ///< y position to start drawing text
int max_glyph_w; ///< max glyph width
int max_glyph_h; ///< max glyph height
int shadowx, shadowy;
int borderw; ///< border width
@@ -565,24 +566,33 @@ static int load_font(AVFilterContext *ctx)
if (!err)
return 0;
#endif
return err;
}
+static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp);
static int load_textfile(AVFilterContext *ctx)
{
DrawTextContext *s = ctx->priv;
int err;
uint8_t *textbuf;
uint8_t *tmp;
size_t textbuf_size;
- if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
+ if ((err = expand_text(ctx, s->textfile, &s->expanded_textfile)) < 0) {
+ av_log(ctx, AV_LOG_ERROR, "The text file path '%s' is not expandable\n",
+ s->textfile);
+ return err;
+ }
+
+ av_log(ctx, AV_LOG_DEBUG, "expanded_textfile:%s\n", s->expanded_textfile.str);
+
+ if ((err = av_file_map(s->expanded_textfile.str, &textbuf, &textbuf_size, 0,
ctx)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"The text file '%s' could not be read or is empty\n",
- s->textfile);
+ s->expanded_textfile.str);
return err;
}
if (textbuf_size > SIZE_MAX - 1 || !(tmp = av_realloc(s->text, textbuf_size +
1))) {
av_file_unmap(textbuf, textbuf_size);
return AVERROR(ENOMEM);
@@ -702,12 +712,14 @@ static av_cold int init(AVFilterContext *ctx)
if (!s->fontfile && !CONFIG_LIBFONTCONFIG) {
av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
return AVERROR(EINVAL);
}
+ av_bprint_init(&s->expanded_textfile, 0, AV_BPRINT_SIZE_UNLIMITED);
+
if (s->textfile) {
if (s->text) {
av_log(ctx, AV_LOG_ERROR,
"Both text and text file provided. Please provide only one\n");
return AVERROR(EINVAL);
}
@@ -820,12 +832,13 @@ static av_cold void uninit(AVFilterContext *ctx)
FT_Done_Face(s->face);
FT_Stroker_Done(s->stroker);
FT_Done_FreeType(s->library);
av_bprint_finalize(&s->expanded_text, NULL);
av_bprint_finalize(&s->expanded_fontcolor, NULL);
+ av_bprint_finalize(&s->expanded_textfile, NULL);
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
DrawTextContext *s = ctx->priv;
Hi David, Not a full review, but a minor point that popped in mind. It is common to pad serially numbered files with 0. E.g. if you have <1000 files, the 9th file will be named file009.txt. Is this case handled by the expansion? Or is it assumed that the text file numbers are not zero-padded? If it the latter is the case, it would be good to make that explicit in the documentation. Of course, accounting for padding would be better, but this may not be straightforward without adding more code. Regards, Manolis On Tue, 19 May 2020 at 06:10, David Andreoletti <david@andreoletti.net> wrote: > Hi ffmpeg maintainers / community, > New contributor here. The patch [0] for the drawtext filter was submitted > some > time ago now but has been reviewed yet. It seems there is no official > maintainer > for this filter (as per the MAINTAINERS file) > What should be done to have it reviewed ? > > [0] > > https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/ > > Regards, > David Andreoletti > > >
Manolis: drawtext's text expansion section [0] does not mention the special
variable %{frame_num} has 0 paddable. When I tested locally (on master), it is
not 0 padded.
Running through different scenario, I recommend the expanded file path to not
contain 0 padded frame number:- if automatic padding is specified, then video
with no total frame known (live stream) would be problematic- if manually
padding is specified, it would complicate drawtext's textfile options parsing:
support for 0 padded %{frame_num} and possibly other custom formatting when
other supported %{....} variables are expanded.
For a first improvement to an existing functionality, I would prefer to keep it
simple and focused :-)
[0]https://ffmpeg.org/ffmpeg-filters.html#Text-expansion
On Tue, May 19, 2020 9:34 AM, Manolis Stamatogiannakis mstamat@gmail.com wrote:
Hi David,
Not a full review, but a minor point that popped in mind.
It is common to pad serially numbered files with 0. E.g. if you have <1000
files, the 9th file will be named file009.txt.
Is this case handled by the expansion? Or is it assumed that the text file
numbers are not zero-padded?
If it the latter is the case, it would be good to make that explicit in the
documentation.
Of course, accounting for padding would be better, but this may not be
straightforward without adding more code.
Regards,
Manolis
On Tue, 19 May 2020 at 06:10, David Andreoletti <david@andreoletti.net>
wrote:
> Hi ffmpeg maintainers / community,
> New contributor here. The patch [0] for the drawtext filter was submitted
> some
> time ago now but has been reviewed yet. It seems there is no official
> maintainer
> for this filter (as per the MAINTAINERS file)
> What should be done to have it reviewed ?
>
> [0]
>
>
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/
>
> Regards,
> David Andreoletti
>
>
>
FFmpeg team,
Is there any other discussion/changes needed to get this contribution merged in
?
Regards,
On Tue, May 19, 2020 12:36 PM, David Andreoletti david@andreoletti.net wrote:
Manolis: drawtext's text expansion section [0] does not mention the special
variable %{frame_num} has 0 paddable. When I tested locally (on master), it is
not 0 padded.
Running through different scenario, I recommend the expanded file path to not
contain 0 padded frame number:- if automatic padding is specified, then video
with no total frame known (live stream) would be problematic- if manually
padding is specified, it would complicate drawtext's textfile options parsing:
support for 0 padded %{frame_num} and possibly other custom formatting when
other supported %{....} variables are expanded.
For a first improvement to an existing functionality, I would prefer to keep it
simple and focused :-)
[0]https://ffmpeg.org/ffmpeg-filters.html#Text-expansion
On Tue, May 19, 2020 9:34 AM, Manolis Stamatogiannakis mstamat@gmail.com wrote:
Hi David,
Not a full review, but a minor point that popped in mind.
It is common to pad serially numbered files with 0. E.g. if you have <1000
files, the 9th file will be named file009.txt.
Is this case handled by the expansion? Or is it assumed that the text file
numbers are not zero-padded?
If it the latter is the case, it would be good to make that explicit in the
documentation.
Of course, accounting for padding would be better, but this may not be
straightforward without adding more code.
Regards,
Manolis
On Tue, 19 May 2020 at 06:10, David Andreoletti <david@andreoletti.net>
wrote:
> Hi ffmpeg maintainers / community,
> New contributor here. The patch [0] for the drawtext filter was submitted
> some
> time ago now but has been reviewed yet. It seems there is no official
> maintainer
> for this filter (as per the MAINTAINERS file)
> What should be done to have it reviewed ?
>
> [0]
>
>
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/
>
> Regards,
> David Andreoletti
>
>
>
**Help needed**: I am still hopeful the patch will get some attention but hope
is fading now (due to summer) :-). It's an easy patch and probably takes
10-20min to review.
Quick patch's status:- it compiles on the latest ffmpeg 4.3,- it passes the
tests,- the associated documentation has been updated with examples (and
documentation builds successfully),- Manolis Stamatogiannakis gave feedback, to
which I replied. No more action on the feedback needed as far as I can tell.-
The patch's age is ~ 2 months and awaiting someone to make it progress (feedback
or merge).
On pathwork [0], a few weeks ago, I assigned it to Michael Niedermayer as a last
resort but I was told on IRC he is super busy.[0]
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/
Any volunteer :-) ?
On Mon, May 25, 2020 4:27 AM, David Andreoletti david@andreoletti.net wrote:
FFmpeg team,
Is there any other discussion/changes needed to get this contribution merged in
?
Regards,
On Tue, May 19, 2020 12:36 PM, David Andreoletti david@andreoletti.net wrote:
Manolis: drawtext's text expansion section [0] does not mention the special
variable %{frame_num} has 0 paddable. When I tested locally (on master), it is
not 0 padded.
Running through different scenario, I recommend the expanded file path to not
contain 0 padded frame number:- if automatic padding is specified, then video
with no total frame known (live stream) would be problematic- if manually
padding is specified, it would complicate drawtext's textfile options parsing:
support for 0 padded %{frame_num} and possibly other custom formatting when
other supported %{....} variables are expanded.
For a first improvement to an existing functionality, I would prefer to keep it
simple and focused :-)
[0]https://ffmpeg.org/ffmpeg-filters.html#Text-expansion
On Tue, May 19, 2020 9:34 AM, Manolis Stamatogiannakis mstamat@gmail.com wrote:
Hi David,
Not a full review, but a minor point that popped in mind.
It is common to pad serially numbered files with 0. E.g. if you have <1000
files, the 9th file will be named file009.txt.
Is this case handled by the expansion? Or is it assumed that the text file
numbers are not zero-padded?
If it the latter is the case, it would be good to make that explicit in the
documentation.
Of course, accounting for padding would be better, but this may not be
straightforward without adding more code.
Regards,
Manolis
On Tue, 19 May 2020 at 06:10, David Andreoletti <david@andreoletti.net>
wrote:
> Hi ffmpeg maintainers / community,
> New contributor here. The patch [0] for the drawtext filter was submitted
> some
> time ago now but has been reviewed yet. It seems there is no official
> maintainer
> for this filter (as per the MAINTAINERS file)
> What should be done to have it reviewed ?
>
> [0]
>
>
https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200511143159.19390-1-david@andreoletti.net/
>
> Regards,
> David Andreoletti
>
>
>
diff --git a/doc/filters.texi b/doc/filters.texi index d19fd346ae..460d65dd88 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -9659,13 +9659,13 @@ The default value of @var{borderw} is 0. Set the color to be used for drawing border around text. For the syntax of this option, check the @ref{color syntax,,"Color" section in the ffmpeg-utils manual,ffmpeg-utils}. The default value of @var{bordercolor} is "black". @item expansion -Select how the @var{text} is expanded. Can be either @code{none}, +Select how the @var{text} and @var{textfile} are expanded. Can be either @code{none}, @code{strftime} (deprecated) or @code{normal} (default). See the @ref{drawtext_expansion, Text expansion} section below for details. @item basetime Set a start time for the count. Value is in microseconds. Only applied @@ -9786,15 +9786,19 @@ of UTF-8 encoded characters. This parameter is mandatory if no text string is specified with the parameter @var{text}. If both @var{text} and @var{textfile} are specified, an error is thrown. +This parameter supports (per frame) variable expansion. Per frame variable +expansion requires @code{reload=1}. See @var{expansion} for details. + + @item reload -If set to 1, the @var{textfile} will be reloaded before each frame. -Be sure to update it atomically, or it may be read partially, or even fail. +If set to 1, then before each frame, @var{textfile} file path will be expanded and then the file at said path will be reloaded. +Be sure to update the file atomically, or it may be read partially, or even fail. @item x @item y The expressions which specify the offsets where text will be drawn within the video frame. They are relative to the top/left border of the output image. @@ -10060,12 +10064,18 @@ drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t" @item Show the content of file @file{CREDITS} off the bottom of the frame and scroll up. @example drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t" @end example +@item +Each frame, reload a different text file at /path/to/frameX.txt, where X is replaced with the frame number being processed by the filter +@example +drawtext="expansion:normal:textfile=/path/to/frame%@{frame_num@}.txt:reload=1" +@end example + @item Draw a single green letter "g", at the center of the input video. The glyph baseline is placed at half screen height. @example drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent" @end example diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c index abe1ca6c35..ffb1ff2330 100644 --- a/libavfilter/vf_drawtext.c +++ b/libavfilter/vf_drawtext.c @@ -152,13 +152,14 @@ typedef struct DrawTextContext { AVBPrint expanded_text; ///< used to contain the expanded text uint8_t *fontcolor_expr; ///< fontcolor expression to evaluate AVBPrint expanded_fontcolor; ///< used to contain the expanded fontcolor spec int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_* FT_Vector *positions; ///< positions for each element in the text size_t nb_positions; ///< number of elements of positions array - char *textfile; ///< file with text to be drawn + char *textfile; ///< filename with text to be drawn + AVBPrint expanded_textfile; ///< Same as textfile, except the filename can be expanded int x; ///< x position to start drawing text int y; ///< y position to start drawing text int max_glyph_w; ///< max glyph width int max_glyph_h; ///< max glyph height int shadowx, shadowy; int borderw; ///< border width @@ -565,24 +566,33 @@ static int load_font(AVFilterContext *ctx) if (!err) return 0; #endif return err; } +static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp); static int load_textfile(AVFilterContext *ctx) { DrawTextContext *s = ctx->priv; int err; uint8_t *textbuf; uint8_t *tmp; size_t textbuf_size; - if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) { + if ((err = expand_text(ctx, s->textfile, &s->expanded_textfile)) < 0) { + av_log(ctx, AV_LOG_ERROR, "The text file path '%s' is not expandable\n", + s->textfile); + return err; + } + + av_log(ctx, AV_LOG_DEBUG, "expanded_textfile:%s\n", s->expanded_textfile.str); + + if ((err = av_file_map(s->expanded_textfile.str, &textbuf, &textbuf_size, 0, ctx)) < 0) { av_log(ctx, AV_LOG_ERROR, "The text file '%s' could not be read or is empty\n", - s->textfile); + s->expanded_textfile.str); return err; } if (textbuf_size > SIZE_MAX - 1 || !(tmp = av_realloc(s->text, textbuf_size + 1))) { av_file_unmap(textbuf, textbuf_size); return AVERROR(ENOMEM); @@ -702,12 +712,14 @@ static av_cold int init(AVFilterContext *ctx) if (!s->fontfile && !CONFIG_LIBFONTCONFIG) { av_log(ctx, AV_LOG_ERROR, "No font filename provided\n"); return AVERROR(EINVAL); } + av_bprint_init(&s->expanded_textfile, 0, AV_BPRINT_SIZE_UNLIMITED); + if (s->textfile) { if (s->text) { av_log(ctx, AV_LOG_ERROR, "Both text and text file provided. Please provide only one\n"); return AVERROR(EINVAL); } @@ -820,12 +832,13 @@ static av_cold void uninit(AVFilterContext *ctx) FT_Done_Face(s->face); FT_Stroker_Done(s->stroker); FT_Done_FreeType(s->library); av_bprint_finalize(&s->expanded_text, NULL); av_bprint_finalize(&s->expanded_fontcolor, NULL); + av_bprint_finalize(&s->expanded_textfile, NULL); } static int config_input(AVFilterLink *inlink) { AVFilterContext *ctx = inlink->dst; DrawTextContext *s = ctx->priv;
drawtext allows a file to be reloaded per frame. However, the file to be reloaded is constant across frame. With textfile now supporting text expansion, a different file can be reloaded per frame. Eg: textfile=/path/fo/file{frame_num}.txt Signed-off-by: David Andreoletti <david@andreoletti.net> --- doc/filters.texi | 16 +++++++++++++--- libavfilter/vf_drawtext.c | 19 ++++++++++++++++--- 2 files changed, 29 insertions(+), 6 deletions(-)