ffmpeg/libavfilter/af_aformat.c

/*
 * Copyright (c) 2011 Mina Nagy Zaki
 *
 * 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
 */

/**
 * @file
 * format audio filter
 */

#include "libavutil/audioconvert.h"
#include "libavutil/avstring.h"
#include "avfilter.h"
#include "internal.h"

typedef struct {
    AVFilterFormats *formats, *chlayouts, *packing;
} AFormatContext;

static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
    AFormatContext * const aformat = ctx->priv;
    char *fmts_str = NULL, *fmt_str, *ptr = NULL;
    int64_t fmt;
    int ret;

    if (!args)
        goto arg_fail;

#define ADD_FORMATS(all_formats, fmt_name, fmt_type, fmts_list)         \
    fmts_str = av_get_token(&args, ":");                                \
    if (!fmts_str || !*fmts_str)                                        \
        goto arg_fail;                                                  \
    if (!strcmp(fmts_str, "all")) {                                     \
        aformat->fmts_list = all_formats;                               \
    } else {                                                            \
        for (fmt_str = fmts_str;                                        \
             fmt_str = av_strtok(fmt_str, ",", &ptr); fmt_str = NULL) { \
            if ((ret = ff_parse_##fmt_name((fmt_type *)&fmt,            \
                                           fmt_str, ctx)) < 0) {        \
                av_freep(&fmts_str);                                    \
                return ret;                                             \
            }                                                           \
            avfilter_add_format(&aformat->fmts_list, fmt);              \
        }                                                               \
    }                                                                   \
    av_freep(&fmts_str);                                                \
    if (*args)                                                          \
        args++;

    ADD_FORMATS(avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO), sample_format, int, formats);
    ADD_FORMATS(avfilter_make_all_channel_layouts(), channel_layout, int64_t, chlayouts);
    ADD_FORMATS(avfilter_make_all_packing_formats(), packing_format, int, packing);

    return 0;

arg_fail:
    av_log(ctx, AV_LOG_ERROR, "Invalid arguments, they must be of the form "
                              "sample_fmts:channel_layouts:packing_fmts\n");
    av_freep(&fmts_str);
    return AVERROR(EINVAL);
}

static int query_formats(AVFilterContext *ctx)
{
    AFormatContext * const aformat = ctx->priv;

    avfilter_set_common_sample_formats (ctx, aformat->formats);
    avfilter_set_common_channel_layouts(ctx, aformat->chlayouts);
    avfilter_set_common_packing_formats(ctx, aformat->packing);
    return 0;
}

static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamplesref)
{
    avfilter_filter_samples(inlink->dst->outputs[0], insamplesref);
}

AVFilter avfilter_af_aformat = {
    .name          = "aformat",
    .description   = NULL_IF_CONFIG_SMALL("Convert the input audio to one of the specified formats."),
    .init          = init,
    .query_formats = query_formats,
    .priv_size     = sizeof(AFormatContext),

    .inputs        = (AVFilterPad[]) {{ .name            = "default",
                                        .type            = AVMEDIA_TYPE_AUDIO,
                                        .filter_samples  = filter_samples},
                                      { .name = NULL}},
    .outputs       = (AVFilterPad[]) {{ .name            = "default",
                                        .type            = AVMEDIA_TYPE_AUDIO},
                                      { .name = NULL}},
};