On date Tuesday 2014-11-11 11:02:32 +0100, wm4 encoded:
> On Tue, 11 Nov 2014 08:31:24 +0100
> Lukasz Marek <lukasz.m.lu...@gmail.com> wrote:
>
> > TODO: bump minor version, update doc/APIchanges
> >
> > Function allows to create string containing object's serialized options.
> > Such string may be passed back to av_set_options_string() in order to
> > restore options.
> >
> > Signed-off-by: Lukasz Marek <lukasz.m.lu...@gmail.com>
> > +Test av_opt_serialize()
> > +num=0,toggle=1,rational=1,string=default,flags=1,size=200x300,pix_fmt=297,sample_fmt=1,video_rate=25,duration=0.001000,color=0xffc0cbff,cl=311,bin=62696e00,bin1=,bin2=,num64=1,flt=0.3333333433,dbl=0.3333333333
> > +num=0,toggle=1,rational=1,string=default,flags=1,size=200x300,pix_fmt=297,sample_fmt=1,video_rate=25,duration=0.001000,color=0xffc0cbff,cl=311,bin=62696e00,bin1=,bin2=,num64=1,flt=0.3333333433,dbl=0.3333333333
> > +
> > Testing av_set_options_string()
> > OK setting options string: ''
> > Error setting options string: ':'
>
[...]
> IMO it's quite WTFish to introduce such extensive functionality that
> is only going to be needed by a single broken thing (FFserver).
No I think this is useful on its own (I had a patch about that, in
attachment, it was part of a larger changeset:
lavu/opt: make av_opt_get() return NULL in case a string is not set
lavu/bprint: add av_bprint_options()
lavc: add "s" and "pix_fmt" options to AVCodecContext
doc: add section "Options lookup order"
lavc: add sample_fmt option
lavc/utils: shows context options
For example it is useful to print the configuration of an encoder, and
copy&paste its configuration from one application to another.
> Can't FFserver's design be fixed instead?
How do you suggest to fix it?
--
FFmpeg = Fundamentalist and Fiendish Mere Puritan Excellent Gadget
>From 32e802c0f6d10fa4284a696f7f2219efad3cf2b4 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefa...@gmail.com>
Date: Mon, 4 Mar 2013 18:30:31 +0100
Subject: [PATCH] lavu/opt: make av_opt_get() return NULL in case a string is
not set
This allows to distinguish between the case when the string is not set,
and the string is set to the empty string.
TODO: bump micro
---
libavutil/opt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavutil/opt.c b/libavutil/opt.c
index c035307..aeea82d 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -600,7 +600,7 @@ int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
if (*(uint8_t**)dst)
*out_val = av_strdup(*(uint8_t**)dst);
else
- *out_val = av_strdup("");
+ *out_val = NULL;
return 0;
case AV_OPT_TYPE_BINARY:
len = *(int*)(((uint8_t *)dst) + sizeof(uint8_t *));
--
1.8.3.2
>From 8b0a701cc17262f649aa0339f55561ee19b9b1b7 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefa...@gmail.com>
Date: Thu, 9 Aug 2012 19:59:48 +0200
Subject: [PATCH] lavu/bprint: add av_bprint_options()
This function will be useful to serialize an object context.
TODO: add APIChanges entry, bump minor
---
libavutil/bprint.c | 23 +++++++++++++++++++++++
libavutil/bprint.h | 15 +++++++++++++++
libavutil/opt.c | 10 +++++++++-
3 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/libavutil/bprint.c b/libavutil/bprint.c
index cd91bc4..64edecb 100644
--- a/libavutil/bprint.c
+++ b/libavutil/bprint.c
@@ -29,6 +29,7 @@
#include "compat/va_copy.h"
#include "error.h"
#include "mem.h"
+#include "opt.h"
#define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size))
#define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer)
@@ -286,6 +287,28 @@ void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_cha
}
}
+void av_bprint_options(struct AVBPrint *bp, void *ctx,
+ const char *key_val_sep, const char *pairs_sep)
+{
+ const AVOption *opt = NULL, *prev_opt = NULL;
+
+ while (opt = av_opt_next(ctx, opt)) {
+ uint8_t *val;
+ char sep[2] = { pairs_sep[0], 0 };
+
+ /* skip duplicated option values */
+ if (prev_opt && prev_opt->offset == opt->offset)
+ continue;
+ av_opt_get(ctx, opt->name, AV_OPT_SEARCH_CHILDREN, &val);
+ if (opt->offset && val) {
+ av_bprintf(bp, "%s%s%c", prev_opt ? sep : "", opt->name, key_val_sep[0]);
+ av_bprint_escape(bp, val, pairs_sep, AV_ESCAPE_MODE_AUTO, 0);
+ av_freep(&val);
+ }
+ prev_opt = opt;
+ }
+}
+
#ifdef TEST
#undef printf
diff --git a/libavutil/bprint.h b/libavutil/bprint.h
index bb1de25..9053703 100644
--- a/libavutil/bprint.h
+++ b/libavutil/bprint.h
@@ -204,4 +204,19 @@ int av_bprint_finalize(AVBPrint *buf, char **ret_str);
void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_chars,
enum AVEscapeMode mode, int flags);
+/**
+ * Append a compact description of the context options to a bprint buffer.
+ * The obtained string is escaped, and can be used to set options through the function
+ * av_opt_set_from_string() or equivalent.
+ *
+ * @param bp already inited destination bprint buffer
+ * @param ctx pointer to a context whose first field is a pointer to an AVClass
+ * @param key_val_sep a 0-terminated list of characters used to separate
+ * key from value, for example '='
+ * @param pairs_sep a 0-terminated list of characters used to separate
+ * two pairs from each other, for example ':' or ','
+ */
+void av_bprint_options(struct AVBPrint *bp, void *ctx,
+ const char *key_val_sep, const char *pairs_sep);
+
#endif /* AVUTIL_BPRINT_H */
diff --git a/libavutil/opt.c b/libavutil/opt.c
index aeea82d..3e35d4f 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -27,7 +27,7 @@
#include "avutil.h"
#include "avstring.h"
-#include "common.h"
+#include "bprint.h"
#include "opt.h"
#include "eval.h"
#include "dict.h"
@@ -1480,6 +1480,7 @@ static const AVOption test_options[]= {
{"lame", "set lame flag ", 0, AV_OPT_TYPE_CONST, {.i64 = TEST_FLAG_LAME}, INT_MIN, INT_MAX, 0, "flags" },
{"mu", "set mu flag ", 0, AV_OPT_TYPE_CONST, {.i64 = TEST_FLAG_MU}, INT_MIN, INT_MAX, 0, "flags" },
{"size", "set size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE,{0}, 0, 0 },
+{"s", "set size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE,{0}, 0, 0 },
{"pix_fmt", "set pixfmt", OFFSET(pix_fmt), AV_OPT_TYPE_PIXEL_FMT, {.i64 = AV_PIX_FMT_NONE}, -1, AV_PIX_FMT_NB-1},
{"sample_fmt", "set samplefmt", OFFSET(sample_fmt), AV_OPT_TYPE_SAMPLE_FMT, {.i64 = AV_SAMPLE_FMT_NONE}, -1, AV_SAMPLE_FMT_NB-1},
{"video_rate", "set videorate", OFFSET(video_rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0 },
@@ -1502,6 +1503,7 @@ static const AVClass test_class = {
int main(void)
{
int i;
+ AVBPrint bp;
printf("\nTesting av_set_options_string()\n");
{
@@ -1559,6 +1561,12 @@ int main(void)
av_log(&test_ctx, AV_LOG_ERROR, "Error setting options string: '%s'\n", options[i]);
printf("\n");
}
+
+ av_bprint_init(&bp, 1, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_options(&bp, &test_ctx, "=", ":");
+ printf("test_ctx=%s\n", bp.str);
+ av_bprint_clear(&bp);
+
av_freep(&test_ctx.string);
}
--
1.8.3.2
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