[FFmpeg-devel] [PATCH 3/4] lavu/opt: implement av_opt_get_key_value().
Stefano Sabatini
stefasab at gmail.com
Sat Nov 3 11:28:15 CET 2012
On date Friday 2012-11-02 13:36:14 +0100, Nicolas George encoded:
> This function does the low-level work of av_opt_set_from_string()
> but can be used when there is no option context or when a generic
> handling of unknown keys is needed.
>
> av_opt_set_from_string() is changed to make use of it.
>
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
> doc/APIchanges | 3 +++
> libavutil/opt.c | 52 +++++++++++++++++++++++++++++++++++++--------------
> libavutil/opt.h | 32 +++++++++++++++++++++++++++++++
> libavutil/version.h | 2 +-
> 4 files changed, 74 insertions(+), 15 deletions(-)
>
> diff --git a/doc/APIchanges b/doc/APIchanges
> index aa82846..fddd73f 100644
> --- a/doc/APIchanges
> +++ b/doc/APIchanges
> @@ -15,6 +15,9 @@ libavutil: 2012-10-22
>
> API changes, most recent first:
>
> +2012-11-02 - xxxxxxx - lavu 52.2.100 - opt.h
> + Add av_opt_get_key_value().
> +
> 2012-10-21 - xxxxxxx - lavc 54.68.100 - avcodec.h
> lavfi 3.20.100 - avfilter.h
> Add AV_PKT_DATA_STRINGS_METADATA side data type, used to transmit key/value
> diff --git a/libavutil/opt.c b/libavutil/opt.c
> index 46f93de..b577500 100644
> --- a/libavutil/opt.c
> +++ b/libavutil/opt.c
> @@ -828,13 +828,37 @@ static int get_key(const char **ropts, const char *delim, char **rkey)
> return 0;
> }
>
> +int av_opt_get_key_value(const char **ropts,
> + const char *key_val_sep, const char *pairs_sep,
> + unsigned flags,
> + char **rkey, char **rval)
> +{
> + int ret;
> + char *key = NULL, *val;
> + const char *opts = *ropts;
> +
> + if ((ret = get_key(&opts, key_val_sep, &key)) < 0 &&
> + !(flags & AV_OPT_FLAG_IMPLICIT_KEY))
> + return AVERROR(EINVAL);
> + if (!(val = av_get_token(&opts, pairs_sep))) {
> + av_free(key);
> + return AVERROR(ENOMEM);
> + }
> + if (*opts && strchr(pairs_sep, *opts))
> + opts++;
> + *ropts = opts;
> + *rkey = key;
> + *rval = val;
maybe you can use directly ropts, rkey, rval
> + return 0;
> +}
> +
> int av_opt_set_from_string(void *ctx, const char *opts,
> const char *const *shorthand,
> const char *key_val_sep, const char *pairs_sep)
> {
> int ret, count = 0;
> const char *dummy_shorthand = NULL;
> - char *parsed_key, *value;
> + char *av_uninit(parsed_key), *av_uninit(value);
What's this useful for?
> const char *key;
>
> if (!opts)
> @@ -843,25 +867,25 @@ int av_opt_set_from_string(void *ctx, const char *opts,
> shorthand = &dummy_shorthand;
>
> while (*opts) {
> - parsed_key = NULL; /* so we can free it anyway */
> - if ((ret = get_key(&opts, key_val_sep, &parsed_key)) < 0) {
> - if (*shorthand) {
> - key = *(shorthand++);
> - } else {
> + ret = av_opt_get_key_value(&opts, key_val_sep, pairs_sep,
> + *shorthand ? AV_OPT_FLAG_IMPLICIT_KEY : 0,
> + &parsed_key, &value);
> + if (ret < 0) {
> + if (ret == AVERROR(EINVAL))
> av_log(ctx, AV_LOG_ERROR, "No option name near '%s'\n", opts);
> - return AVERROR(EINVAL);
> - }
> - } else {
> + else
> + av_log(ctx, AV_LOG_ERROR, "Unable to parse '%s': %s\n", opts,
> + av_err2str(ret));
> + return ret;
> + }
> + if (parsed_key) {
> key = parsed_key;
> while (*shorthand) /* discard all remaining shorthand */
> shorthand++;
> + } else {
> + key = *(shorthand++);
> }
>
> - if (!(value = av_get_token(&opts, pairs_sep)))
> - return AVERROR(ENOMEM);
> - if (*opts && strchr(pairs_sep, *opts))
> - opts++;
> -
> av_log(ctx, AV_LOG_DEBUG, "Setting '%s' to value '%s'\n", key, value);
> if ((ret = av_opt_set(ctx, key, value, 0)) < 0) {
> if (ret == AVERROR_OPTION_NOT_FOUND)
> diff --git a/libavutil/opt.h b/libavutil/opt.h
> index 81fefd9..a1165f0 100644
> --- a/libavutil/opt.h
> +++ b/libavutil/opt.h
> @@ -455,6 +455,38 @@ int av_opt_flag_is_set(void *obj, const char *field_name, const char *flag_name)
> int av_opt_set_dict(void *obj, struct AVDictionary **options);
>
> /**
> + * Extract a key-value pair from the beginning of a string.
> + *
> + * @param ropts pointer to the options string, will be updated to
> + * point to the rest of the string
> + * @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 ','
> + * @param flags flags; see the AV_OPT_FLAG_* values below
> + * @param rkey parsed key; must be freed using av_free()
> + * @param rval parsed value; must be freed using av_free()
Possibly mention what "r" stands for (return or whatever).
> + *
> + * @return 0 for success, or a negative value corresponding to an AVERROR
> + * code in case of error; in particular:
> + * AVERROR(EINVAL) if no key is present
> + *
> + */
> +int av_opt_get_key_value(const char **ropts,
> + const char *key_val_sep, const char *pairs_sep,
> + unsigned flags,
> + char **rkey, char **rval);
> +
> +enum {
> +
> + /**
> + * Accept to parse a value without a key; the key will then be returned
> + * as NULL
Final dot missing
> + */
> + AV_OPT_FLAG_IMPLICIT_KEY = 1,
> +};
> +
> +/**
> * @defgroup opt_eval_funcs Evaluating option strings
> * @{
> * This group of functions can be used to evaluate option strings
> diff --git a/libavutil/version.h b/libavutil/version.h
> index 94a4a47..60a7450 100644
> --- a/libavutil/version.h
> +++ b/libavutil/version.h
> @@ -75,7 +75,7 @@
> */
>
> #define LIBAVUTIL_VERSION_MAJOR 52
> -#define LIBAVUTIL_VERSION_MINOR 1
> +#define LIBAVUTIL_VERSION_MINOR 2
> #define LIBAVUTIL_VERSION_MICRO 100
>
> #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \
LGTM, thanks.
--
FFmpeg = Fierce and Free Mastodontic Portable Ecumenical God
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