diff options
Diffstat (limited to 'libavfilter/asrc_anullsrc.c')
-rw-r--r-- | libavfilter/asrc_anullsrc.c | 117 |
1 files changed, 105 insertions, 12 deletions
diff --git a/libavfilter/asrc_anullsrc.c b/libavfilter/asrc_anullsrc.c index b1a449c..28d4500 100644 --- a/libavfilter/asrc_anullsrc.c +++ b/libavfilter/asrc_anullsrc.c @@ -1,18 +1,21 @@ /* - * This file is part of Libav. + * Copyright 2010 S.N. Hemanth Meenakshisundaram <smeenaks ucsd edu> + * Copyright 2010 Stefano Sabatini <stefano.sabatini-lala poste it> * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -26,28 +29,118 @@ #include "libavutil/channel_layout.h" #include "libavutil/internal.h" +#include "libavutil/opt.h" +#include "audio.h" #include "avfilter.h" #include "internal.h" -static int request_frame(AVFilterLink *link) +typedef struct { + const AVClass *class; + char *channel_layout_str; + uint64_t channel_layout; + char *sample_rate_str; + int sample_rate; + int nb_samples; ///< number of samples per requested frame + int64_t pts; +} ANullContext; + +#define OFFSET(x) offsetof(ANullContext, x) +#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption anullsrc_options[]= { + { "channel_layout", "set channel_layout", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, FLAGS }, + { "cl", "set channel_layout", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, {.str = "stereo"}, 0, 0, FLAGS }, + { "sample_rate", "set sample rate", OFFSET(sample_rate_str) , AV_OPT_TYPE_STRING, {.str = "44100"}, 0, 0, FLAGS }, + { "r", "set sample rate", OFFSET(sample_rate_str) , AV_OPT_TYPE_STRING, {.str = "44100"}, 0, 0, FLAGS }, + { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS }, + { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 0, INT_MAX, FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(anullsrc); + +static av_cold int init(AVFilterContext *ctx) { - return AVERROR_EOF; + ANullContext *null = ctx->priv; + int ret; + + if ((ret = ff_parse_sample_rate(&null->sample_rate, + null->sample_rate_str, ctx)) < 0) + return ret; + + if ((ret = ff_parse_channel_layout(&null->channel_layout, NULL, + null->channel_layout_str, ctx)) < 0) + return ret; + + return 0; +} + +static int query_formats(AVFilterContext *ctx) +{ + ANullContext *null = ctx->priv; + int64_t chlayouts[] = { null->channel_layout, -1 }; + int sample_rates[] = { null->sample_rate, -1 }; + + ff_set_common_formats (ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO)); + ff_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts)); + ff_set_common_samplerates (ctx, ff_make_format_list(sample_rates)); + + return 0; +} + +static int config_props(AVFilterLink *outlink) +{ + ANullContext *null = outlink->src->priv; + char buf[128]; + + av_get_channel_layout_string(buf, sizeof(buf), 0, null->channel_layout); + av_log(outlink->src, AV_LOG_VERBOSE, + "sample_rate:%d channel_layout:'%s' nb_samples:%d\n", + null->sample_rate, buf, null->nb_samples); + + return 0; +} + +static int request_frame(AVFilterLink *outlink) +{ + int ret; + ANullContext *null = outlink->src->priv; + AVFrame *samplesref; + + samplesref = ff_get_audio_buffer(outlink, null->nb_samples); + if (!samplesref) + return AVERROR(ENOMEM); + + samplesref->pts = null->pts; + samplesref->channel_layout = null->channel_layout; + samplesref->sample_rate = outlink->sample_rate; + + ret = ff_filter_frame(outlink, av_frame_clone(samplesref)); + av_frame_free(&samplesref); + if (ret < 0) + return ret; + + null->pts += null->nb_samples; + return ret; } static const AVFilterPad avfilter_asrc_anullsrc_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, + .config_props = config_props, .request_frame = request_frame, }, { NULL } }; AVFilter ff_asrc_anullsrc = { - .name = "anullsrc", - .description = NULL_IF_CONFIG_SMALL("Null audio source, never return audio frames."), - - .inputs = NULL, - - .outputs = avfilter_asrc_anullsrc_outputs, + .name = "anullsrc", + .description = NULL_IF_CONFIG_SMALL("Null audio source, return empty audio frames."), + .init = init, + .query_formats = query_formats, + .priv_size = sizeof(ANullContext), + .inputs = NULL, + .outputs = avfilter_asrc_anullsrc_outputs, + .priv_class = &anullsrc_class, }; |