[FFmpeg-devel] [PATCH] lavf: add data: URI scheme.

[Stefano Sabatini]

On date Tuesday 2013-01-01 15:46:40 +0100, Nicolas George encoded:
> 
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
>  Changelog                |    1 +
>  doc/protocols.texi       |    9 ++++
>  libavformat/Makefile     |    1 +
>  libavformat/allformats.c |    1 +
>  libavformat/data_uri.c   |  115 ++++++++++++++++++++++++++++++++++++++++++++++
>  libavformat/version.h    |    4 +-
>  6 files changed, 129 insertions(+), 2 deletions(-)
>  create mode 100644 libavformat/data_uri.c
> 
> 
> Addresses Stefano's and Clément's comments. Will push very soon unless
> someone objects.
> 
> 
> diff --git a/Changelog b/Changelog
> index a5144ea..7bea6af 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -53,6 +53,7 @@ version <next>:
>  - MPL2, VPlayer, MPlayer, AQTitle, PJS and SubViewer v1 subtitles demuxers and decoders
>  - Sony Wave64 muxer
>  - adobe and limelight publisher authentication in RTMP
> +- data: URI scheme
>  
>  
>  version 1.0:
> diff --git a/doc/protocols.texi b/doc/protocols.texi
> index e790459..a36d2a3 100644
> --- a/doc/protocols.texi
> +++ b/doc/protocols.texi
> @@ -75,6 +75,15 @@ ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
>  Note that you may need to escape the character "|" which is special for
>  many shells.
>  
> + at section data
> +
> +Data in-line in the URI. See @url{http://en.wikipedia.org/wiki/Data_URI_scheme}.
> +
> +For example, to convert a GIF file given inline with @command{ffmpeg}:
> + at example
> +ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
> + at end example
> +
>  @section file
>  
>  File access protocol.
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index ae3e60d..2266dee 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -408,6 +408,7 @@ OBJS-$(CONFIG_BLURAY_PROTOCOL)           += bluray.o
>  OBJS-$(CONFIG_CACHE_PROTOCOL)            += cache.o
>  OBJS-$(CONFIG_CONCAT_PROTOCOL)           += concat.o
>  OBJS-$(CONFIG_CRYPTO_PROTOCOL)           += crypto.o
> +OBJS-$(CONFIG_DATA_PROTOCOL)             += data_uri.o
>  OBJS-$(CONFIG_FFRTMPCRYPT_PROTOCOL)      += rtmpcrypt.o rtmpdh.o
>  OBJS-$(CONFIG_FFRTMPHTTP_PROTOCOL)       += rtmphttp.o
>  OBJS-$(CONFIG_FILE_PROTOCOL)             += file.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index bb8888b..3946609 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -306,6 +306,7 @@ void av_register_all(void)
>      REGISTER_PROTOCOL(CACHE,            cache);
>      REGISTER_PROTOCOL(CONCAT,           concat);
>      REGISTER_PROTOCOL(CRYPTO,           crypto);
> +    REGISTER_PROTOCOL(DATA,             data);
>      REGISTER_PROTOCOL(FFRTMPCRYPT,      ffrtmpcrypt);
>      REGISTER_PROTOCOL(FFRTMPHTTP,       ffrtmphttp);
>      REGISTER_PROTOCOL(FILE,             file);
> diff --git a/libavformat/data_uri.c b/libavformat/data_uri.c
> new file mode 100644
> index 0000000..36b5060
> --- /dev/null
> +++ b/libavformat/data_uri.c
> @@ -0,0 +1,115 @@
> +/*
> + * Copyright (c) 2012 Nicolas George
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public License
> + * as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public License
> + * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <string.h>
> +#include "libavutil/avstring.h"
> +#include "libavutil/base64.h"
> +#include "url.h"
> +
> +typedef struct {
> +    const uint8_t *data;
> +    void *tofree;
> +    size_t size;
> +    size_t pos;
> +} DataContext;
> +
> +static av_cold int data_open(URLContext *h, const char *uri, int flags)
> +{
> +    DataContext *dc = h->priv_data;
> +    const char *data, *opt, *next;
> +    char *ddata;
> +    int ret, base64 = 0;
> +    size_t in_size;
> +
> +    /* data:content/type[;base64],payload */
> +
> +    av_strstart(uri, "data:", &uri);
> +    data = strchr(uri, ',');
> +    if (!data) {
> +        av_log(h, AV_LOG_ERROR, "No ',' delimiter in URI\n");
> +        return AVERROR(EINVAL);
> +    }
> +    opt = uri;
> +    while (opt < data) {
> +        next = av_x_if_null(memchr(opt, ';', data - opt), data);
> +        if (opt == uri) {
> +            if (!memchr(opt, '/', next - opt)) /* basic validity check */
> +                return AVERROR(EINVAL);
> +            av_log(h, AV_LOG_VERBOSE, "Content-type: %.*s\n",
> +                   (int)(next - opt), opt);
> +        } else {
> +            if (!av_strncasecmp(opt, "base64", next - opt)) {
> +                base64 = 1;
> +            } else {
> +                av_log(h, AV_LOG_VERBOSE, "Ignoring option '%.*s'\n",
> +                       (int)(next - opt), opt);
> +            }
> +        }
> +        opt = next + 1;
> +    }
> +
> +    data++;
> +    in_size = strlen(data);


> +    if (base64) {
> +        size_t out_size = AV_BASE64_SIZE(in_size);

Now this is oversized, since you're using the *encode* buffer size.

> +
> +        if (out_size > INT_MAX || !(ddata = av_malloc(out_size)))
> +            return AVERROR(ENOMEM);
> +        if ((ret = av_base64_decode(ddata, data, out_size)) < 0) {
> +            av_free(ddata);

> +            av_log(h, AV_LOG_ERROR, "Invalid base64 in URI\n");

Nit: base64-encoded data in URI.

[...]

Looks good otherwise, thanks.
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