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-rw-r--r--audio/filter/af_lavfi.c306
1 files changed, 306 insertions, 0 deletions
diff --git a/audio/filter/af_lavfi.c b/audio/filter/af_lavfi.c
new file mode 100644
index 0000000000..6fe0853d07
--- /dev/null
+++ b/audio/filter/af_lavfi.c
@@ -0,0 +1,306 @@
+/*
+ * This file is part of mpv.
+ *
+ * Filter graph creation code taken from FFmpeg ffplay.c (LGPL 2.1 or later)
+ *
+ * mpv is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * mpv 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with mpv. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <assert.h>
+
+#include <libavutil/avstring.h>
+#include <libavutil/mem.h>
+#include <libavutil/mathematics.h>
+#include <libavutil/rational.h>
+#include <libavutil/samplefmt.h>
+#include <libavutil/time.h>
+#include <libavutil/opt.h>
+#include <libavfilter/avfilter.h>
+#include <libavfilter/avfiltergraph.h>
+#include <libavfilter/buffersink.h>
+#include <libavfilter/buffersrc.h>
+
+#include "audio/format.h"
+#include "audio/fmt-conversion.h"
+#include "af.h"
+
+#define IS_LIBAV_FORK (LIBAVFILTER_VERSION_MICRO < 100)
+
+// FFmpeg and Libav have slightly different APIs, just enough to cause us
+// unnecessary pain. <Expletive deleted.>
+#if IS_LIBAV_FORK
+#define graph_parse(graph, filters, inputs, outputs, log_ctx) \
+ avfilter_graph_parse(graph, filters, inputs, outputs, log_ctx)
+#else
+#define graph_parse(graph, filters, inputs, outputs, log_ctx) \
+ avfilter_graph_parse(graph, filters, &(inputs), &(outputs), log_ctx)
+#endif
+
+struct priv {
+ AVFilterGraph *graph;
+ AVFilterContext *in;
+ AVFilterContext *out;
+
+ // Guarantee that the data stays valid until next filter call
+ char *out_buffer;
+
+ struct mp_audio data;
+ struct mp_audio temp;
+
+ int64_t bytes_in;
+ int64_t bytes_out;
+
+ AVRational timebase_out;
+
+ // options
+ char *cfg_graph;
+};
+
+static void destroy_graph(struct af_instance *af)
+{
+ struct priv *p = af->setup;
+ avfilter_graph_free(&p->graph);
+ p->in = p->out = NULL;
+}
+
+static bool recreate_graph(struct af_instance *af, struct mp_audio *config)
+{
+ void *tmp = talloc_new(NULL);
+ struct priv *p = af->setup;
+ AVFilterContext *in = NULL, *out = NULL;
+ int r;
+
+ if (bstr0(p->cfg_graph).len == 0) {
+ mp_msg(MSGT_AFILTER, MSGL_FATAL, "lavfi: no filter graph set\n");
+ return false;
+ }
+
+ destroy_graph(af);
+ mp_msg(MSGT_AFILTER, MSGL_V, "lavfi: create graph: '%s'\n", p->cfg_graph);
+
+ AVFilterGraph *graph = avfilter_graph_alloc();
+ if (!graph)
+ goto error;
+
+ AVFilterInOut *outputs = avfilter_inout_alloc();
+ AVFilterInOut *inputs = avfilter_inout_alloc();
+ if (!outputs || !inputs)
+ goto error;
+
+ char *src_args = talloc_asprintf(tmp,
+ "sample_rate=%d:sample_fmt=%s:channels=%d:time_base=%d/%d:"
+ "channel_layout=0x%"PRIx64, config->rate,
+ av_get_sample_fmt_name(af_to_avformat(config->format)),
+ config->channels.num, 1, config->rate,
+ mp_chmap_to_lavc(&config->channels));
+
+ if (avfilter_graph_create_filter(&in, avfilter_get_by_name("abuffer"),
+ "src", src_args, NULL, graph) < 0)
+ goto error;
+
+ if (avfilter_graph_create_filter(&out, avfilter_get_by_name("abuffersink"),
+ "out", NULL, NULL, graph) < 0)
+ goto error;
+
+ static const enum AVSampleFormat sample_fmts[] = {
+ AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32,
+ AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_DBL,
+ AV_SAMPLE_FMT_NONE
+ };
+ r = av_opt_set_int_list(out, "sample_fmts", sample_fmts,
+ AV_SAMPLE_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
+ if (r < 0)
+ goto error;
+
+ r = av_opt_set_int(out, "all_channel_counts", 1, AV_OPT_SEARCH_CHILDREN);
+ if (r < 0)
+ goto error;
+
+ outputs->name = av_strdup("in");
+ outputs->filter_ctx = in;
+
+ inputs->name = av_strdup("out");
+ inputs->filter_ctx = out;
+
+ if (graph_parse(graph, p->cfg_graph, inputs, outputs, NULL) < 0)
+ goto error;
+
+ if (avfilter_graph_config(graph, NULL) < 0)
+ goto error;
+
+ p->in = in;
+ p->out = out;
+ p->graph = graph;
+
+ assert(out->nb_inputs == 1);
+ assert(in->nb_outputs == 1);
+
+ talloc_free(tmp);
+ return true;
+
+error:
+ mp_msg(MSGT_AFILTER, MSGL_FATAL, "Can't configure libavfilter graph.\n");
+ avfilter_graph_free(&graph);
+ talloc_free(tmp);
+ return false;
+}
+
+static int control(struct af_instance *af, int cmd, void *arg)
+{
+ struct priv *p = af->setup;
+
+ switch (cmd) {
+ case AF_CONTROL_REINIT: {
+ struct mp_audio *in = arg;
+ struct mp_audio orig_in = *in;
+ struct mp_audio *out = af->data;
+
+ if (af_to_avformat(in->format) == AV_SAMPLE_FMT_NONE)
+ mp_audio_set_format(in, AF_FORMAT_FLOAT_NE);
+
+ if (!mp_chmap_is_lavc(&in->channels))
+ mp_chmap_reorder_to_lavc(&in->channels); // will always work
+
+ if (!recreate_graph(af, in))
+ return AF_ERROR;
+
+ AVFilterLink *l_out = p->out->inputs[0];
+
+ out->rate = l_out->sample_rate;
+
+ mp_audio_set_format(out, af_from_avformat(l_out->format));
+
+ struct mp_chmap out_cm;
+ mp_chmap_from_lavc(&out_cm, l_out->channel_layout);
+ if (!out_cm.num || out_cm.num != l_out->channels)
+ mp_chmap_from_channels(&out_cm, l_out->channels);
+ mp_audio_set_channels(out, &out_cm);
+
+ p->timebase_out = l_out->time_base;
+
+ af->mul = (double) (out->rate * out->nch) / (in->rate * in->nch);
+
+ return mp_audio_config_equals(in, &orig_in) ? AF_OK : AF_FALSE;
+ }
+ case AF_CONTROL_COMMAND_LINE: {
+ talloc_free(p->cfg_graph);
+ p->cfg_graph = talloc_strdup(p, (char *)arg);
+ return AF_OK;
+ }
+ }
+ return AF_UNKNOWN;
+}
+
+static struct mp_audio *play(struct af_instance *af, struct mp_audio *data)
+{
+ struct priv *p = af->setup;
+
+ AVFilterLink *l_in = p->in->outputs[0];
+
+ struct mp_audio *r = &p->temp;
+ *r = *af->data;
+
+ int in_frame_size = data->bps * data->channels.num;
+ int out_frame_size = r->bps * r->channels.num;
+
+ AVFrame *frame = av_frame_alloc();
+ frame->nb_samples = data->len / in_frame_size;
+ frame->format = l_in->format;
+
+ // Timebase is 1/sample_rate
+ frame->pts = p->bytes_in / in_frame_size;
+
+ av_frame_set_channels(frame, l_in->channels);
+ av_frame_set_channel_layout(frame, l_in->channel_layout);
+ av_frame_set_sample_rate(frame, l_in->sample_rate);
+
+ frame->data[0] = data->audio;
+ frame->extended_data = frame->data;
+
+ if (av_buffersrc_add_frame(p->in, frame) < 0) {
+ av_frame_free(&frame);
+ return NULL;
+ }
+ av_frame_free(&frame);
+
+ int64_t out_pts = AV_NOPTS_VALUE;
+ size_t out_len = 0;
+ for (;;) {
+ frame = av_frame_alloc();
+ if (av_buffersink_get_frame(p->out, frame) < 0) {
+ // Not an error situation - no more output buffers in queue.
+ av_frame_free(&frame);
+ break;
+ }
+
+ size_t new_len = out_len + frame->nb_samples * out_frame_size;
+ if (new_len > talloc_get_size(p->out_buffer))
+ p->out_buffer = talloc_realloc(p, p->out_buffer, char, new_len);
+ memcpy(p->out_buffer + out_len, frame->data[0], new_len - out_len);
+ out_len = new_len;
+ if (out_pts == AV_NOPTS_VALUE)
+ out_pts = frame->pts;
+
+ av_frame_free(&frame);
+ }
+
+ r->audio = p->out_buffer;
+ r->len = out_len;
+
+ p->bytes_in += data->len;
+ p->bytes_out += r->len;
+
+ if (out_pts != AV_NOPTS_VALUE) {
+ int64_t num_in_frames = p->bytes_in / in_frame_size;
+ double in_time = num_in_frames / (double)data->rate;
+
+ double out_time = out_pts * av_q2d(p->timebase_out);
+ // Need pts past the last output sample.
+ int out_frames = r->len / out_frame_size;
+ out_time += out_frames / (double)r->rate;
+
+ af->delay = (in_time - out_time) * r->rate * out_frame_size;
+ }
+
+ return r;
+}
+
+static void uninit(struct af_instance *af)
+{
+ talloc_free(af->setup);
+}
+
+static int af_open(struct af_instance *af)
+{
+ af->control = control;
+ af->uninit = uninit;
+ af->play = play;
+ af->mul = 1;
+ struct priv *priv = talloc_zero(NULL, struct priv);
+ af->setup = priv;
+ af->data = &priv->data;
+ return AF_OK;
+}
+
+struct af_info af_info_lavfi = {
+ "libavfilter bridge",
+ "lavfi",
+ "",
+ "",
+ 0,
+ af_open
+};