| /* |
| * This file is part of Libav. |
| * |
| * Libav 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, |
| * 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 |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavresample/avresample.h" |
| #include "libavutil/audio_fifo.h" |
| #include "libavutil/mathematics.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/samplefmt.h" |
| |
| #include "audio.h" |
| #include "avfilter.h" |
| |
| typedef struct ASyncContext { |
| const AVClass *class; |
| |
| AVAudioResampleContext *avr; |
| int64_t pts; ///< timestamp in samples of the first sample in fifo |
| int min_delta; ///< pad/trim min threshold in samples |
| |
| /* options */ |
| int resample; |
| float min_delta_sec; |
| int max_comp; |
| } ASyncContext; |
| |
| #define OFFSET(x) offsetof(ASyncContext, x) |
| #define A AV_OPT_FLAG_AUDIO_PARAM |
| static const AVOption options[] = { |
| { "compensate", "Stretch/squeeze the data to make it match the timestamps", OFFSET(resample), AV_OPT_TYPE_INT, { 0 }, 0, 1, A }, |
| { "min_delta", "Minimum difference between timestamps and audio data " |
| "(in seconds) to trigger padding/trimmin the data.", OFFSET(min_delta_sec), AV_OPT_TYPE_FLOAT, { 0.1 }, 0, INT_MAX, A }, |
| { "max_comp", "Maximum compensation in samples per second.", OFFSET(max_comp), AV_OPT_TYPE_INT, { 500 }, 0, INT_MAX, A }, |
| { NULL }, |
| }; |
| |
| static const AVClass async_class = { |
| .class_name = "asyncts filter", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| static int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| ASyncContext *s = ctx->priv; |
| int ret; |
| |
| s->class = &async_class; |
| av_opt_set_defaults(s); |
| |
| if ((ret = av_set_options_string(s, args, "=", ":")) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error parsing options string '%s'.\n", args); |
| return ret; |
| } |
| av_opt_free(s); |
| |
| s->pts = AV_NOPTS_VALUE; |
| |
| return 0; |
| } |
| |
| static void uninit(AVFilterContext *ctx) |
| { |
| ASyncContext *s = ctx->priv; |
| |
| if (s->avr) { |
| avresample_close(s->avr); |
| avresample_free(&s->avr); |
| } |
| } |
| |
| static int config_props(AVFilterLink *link) |
| { |
| ASyncContext *s = link->src->priv; |
| int ret; |
| |
| s->min_delta = s->min_delta_sec * link->sample_rate; |
| link->time_base = (AVRational){1, link->sample_rate}; |
| |
| s->avr = avresample_alloc_context(); |
| if (!s->avr) |
| return AVERROR(ENOMEM); |
| |
| av_opt_set_int(s->avr, "in_channel_layout", link->channel_layout, 0); |
| av_opt_set_int(s->avr, "out_channel_layout", link->channel_layout, 0); |
| av_opt_set_int(s->avr, "in_sample_fmt", link->format, 0); |
| av_opt_set_int(s->avr, "out_sample_fmt", link->format, 0); |
| av_opt_set_int(s->avr, "in_sample_rate", link->sample_rate, 0); |
| av_opt_set_int(s->avr, "out_sample_rate", link->sample_rate, 0); |
| |
| if (s->resample) |
| av_opt_set_int(s->avr, "force_resampling", 1, 0); |
| |
| if ((ret = avresample_open(s->avr)) < 0) |
| return ret; |
| |
| return 0; |
| } |
| |
| static int request_frame(AVFilterLink *link) |
| { |
| AVFilterContext *ctx = link->src; |
| ASyncContext *s = ctx->priv; |
| int ret = avfilter_request_frame(ctx->inputs[0]); |
| int nb_samples; |
| |
| /* flush the fifo */ |
| if (ret == AVERROR_EOF && (nb_samples = avresample_get_delay(s->avr))) { |
| AVFilterBufferRef *buf = ff_get_audio_buffer(link, AV_PERM_WRITE, |
| nb_samples); |
| if (!buf) |
| return AVERROR(ENOMEM); |
| avresample_convert(s->avr, (void**)buf->extended_data, buf->linesize[0], |
| nb_samples, NULL, 0, 0); |
| buf->pts = s->pts; |
| ff_filter_samples(link, buf); |
| return 0; |
| } |
| |
| return ret; |
| } |
| |
| static void write_to_fifo(ASyncContext *s, AVFilterBufferRef *buf) |
| { |
| avresample_convert(s->avr, NULL, 0, 0, (void**)buf->extended_data, |
| buf->linesize[0], buf->audio->nb_samples); |
| avfilter_unref_buffer(buf); |
| } |
| |
| /* get amount of data currently buffered, in samples */ |
| static int64_t get_delay(ASyncContext *s) |
| { |
| return avresample_available(s->avr) + avresample_get_delay(s->avr); |
| } |
| |
| static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| ASyncContext *s = ctx->priv; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| int nb_channels = av_get_channel_layout_nb_channels(buf->audio->channel_layout); |
| int64_t pts = (buf->pts == AV_NOPTS_VALUE) ? buf->pts : |
| av_rescale_q(buf->pts, inlink->time_base, outlink->time_base); |
| int out_size; |
| int64_t delta; |
| |
| /* buffer data until we get the first timestamp */ |
| if (s->pts == AV_NOPTS_VALUE) { |
| if (pts != AV_NOPTS_VALUE) { |
| s->pts = pts - get_delay(s); |
| } |
| write_to_fifo(s, buf); |
| return; |
| } |
| |
| /* now wait for the next timestamp */ |
| if (pts == AV_NOPTS_VALUE) { |
| write_to_fifo(s, buf); |
| return; |
| } |
| |
| /* when we have two timestamps, compute how many samples would we have |
| * to add/remove to get proper sync between data and timestamps */ |
| delta = pts - s->pts - get_delay(s); |
| out_size = avresample_available(s->avr); |
| |
| if (labs(delta) > s->min_delta) { |
| av_log(ctx, AV_LOG_VERBOSE, "Discontinuity - %"PRId64" samples.\n", delta); |
| out_size += delta; |
| } else { |
| if (s->resample) { |
| int comp = av_clip(delta, -s->max_comp, s->max_comp); |
| av_log(ctx, AV_LOG_VERBOSE, "Compensating %d samples per second.\n", comp); |
| avresample_set_compensation(s->avr, delta, inlink->sample_rate); |
| } |
| delta = 0; |
| } |
| |
| if (out_size > 0) { |
| AVFilterBufferRef *buf_out = ff_get_audio_buffer(outlink, AV_PERM_WRITE, |
| out_size); |
| if (!buf_out) |
| return; |
| |
| avresample_read(s->avr, (void**)buf_out->extended_data, out_size); |
| buf_out->pts = s->pts; |
| |
| if (delta > 0) { |
| av_samples_set_silence(buf_out->extended_data, out_size - delta, |
| delta, nb_channels, buf->format); |
| } |
| ff_filter_samples(outlink, buf_out); |
| } else { |
| av_log(ctx, AV_LOG_WARNING, "Non-monotonous timestamps, dropping " |
| "whole buffer.\n"); |
| } |
| |
| /* drain any remaining buffered data */ |
| avresample_read(s->avr, NULL, avresample_available(s->avr)); |
| |
| s->pts = pts - avresample_get_delay(s->avr); |
| avresample_convert(s->avr, NULL, 0, 0, (void**)buf->extended_data, |
| buf->linesize[0], buf->audio->nb_samples); |
| avfilter_unref_buffer(buf); |
| } |
| |
| AVFilter avfilter_af_asyncts = { |
| .name = "asyncts", |
| .description = NULL_IF_CONFIG_SMALL("Sync audio data to timestamps"), |
| |
| .init = init, |
| .uninit = uninit, |
| |
| .priv_size = sizeof(ASyncContext), |
| |
| .inputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .filter_samples = filter_samples }, |
| { NULL }}, |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_AUDIO, |
| .config_props = config_props, |
| .request_frame = request_frame }, |
| { NULL }}, |
| }; |