[FFmpeg-devel] [PATCH] GSoC 2023: Add Audio Overlay Filter
Harshit Karwal
karwalharshit at gmail.com
Wed Aug 23 13:11:44 EEST 2023
1. Added af_aoverlay.c
2. Updated filter documentation
3. Included the filter in libavfilter/Makefile and libavfilter/allfilters.c
Signed-off-by: Harshit Karwal <karwalharshit at gmail.com>
---
doc/filters.texi | 40 +++
libavfilter/Makefile | 1 +
libavfilter/af_aoverlay.c | 623 ++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
4 files changed, 665 insertions(+)
create mode 100644 libavfilter/af_aoverlay.c
diff --git a/doc/filters.texi b/doc/filters.texi
index cac1ee43810..f6a2ab9743e 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2709,6 +2709,46 @@ This filter supports the same commands as options, excluding option @code{order}
Pass the audio source unchanged to the output.
+ at section aoverlay
+
+Replace a specified section of an audio stream with another input audio stream.
+
+In case no enable option for timeline editing is specified, the second audio stream will
+be output at sections of the first stream which have a gap in PTS (Presentation TimeStamp) values
+such that the output stream's PTS values are monotonous.
+
+This filter also supports linear cross fading when transitioning from one
+input stream to another.
+
+The filter accepts the following option:
+
+ at table @option
+ at item cf_duration
+Set duration (in seconds) for cross fade between the inputs. Default value is @code{100} milliseconds.
+ at end table
+
+ at subsection Examples
+
+ at itemize
+ at item
+Replace the first stream with the second stream from @code{t=10} seconds to @code{t=20} seconds:
+ at example
+ffmpeg -i first.wav -i second.wav -filter_complex "aoverlay=enable='between(t,10,20)'" output.wav
+ at end example
+
+ at item
+Do the same as above, but with crossfading for @code{2} seconds between the streams:
+ at example
+ffmpeg -i first.wav -i second.wav -filter_complex "aoverlay=cf_duration=2:enable='between(t,10,20)'" output.wav
+ at end example
+
+ at item
+Introduce a PTS gap from @code{t=4} seconds to @code{t=8} seconds in the first stream and output the second stream during this gap:
+ at example
+ffmpeg -i first.wav -i second.wav -filter_complex "[0]aselect='not(between(t,4,8))'[temp];[temp][1]aoverlay[out]" -map "[out]" output.wav
+ at end example
+ at end itemize
+
@section apad
Pad the end of an audio stream with silence.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 2fe0033b218..c469380038f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -80,6 +80,7 @@ OBJS-$(CONFIG_ANLMDN_FILTER) += af_anlmdn.o
OBJS-$(CONFIG_ANLMF_FILTER) += af_anlms.o
OBJS-$(CONFIG_ANLMS_FILTER) += af_anlms.o
OBJS-$(CONFIG_ANULL_FILTER) += af_anull.o
+OBJS-$(CONFIG_AOVERLAY_FILTER) += af_aoverlay.o
OBJS-$(CONFIG_APAD_FILTER) += af_apad.o
OBJS-$(CONFIG_APERMS_FILTER) += f_perms.o
OBJS-$(CONFIG_APHASER_FILTER) += af_aphaser.o generate_wave_table.o
diff --git a/libavfilter/af_aoverlay.c b/libavfilter/af_aoverlay.c
new file mode 100644
index 00000000000..ea0759fc856
--- /dev/null
+++ b/libavfilter/af_aoverlay.c
@@ -0,0 +1,623 @@
+/*
+ * Copyright (c) 2023 Harshit Karwal
+ *
+ * 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 "libavutil/opt.h"
+#include "libavutil/log.h"
+
+#include "audio.h"
+#include "avfilter.h"
+#include "filters.h"
+#include "internal.h"
+#include "formats.h"
+
+typedef struct FrameRingBuffer {
+ uint8_t *extended_data_buffer;
+ int capacity;
+ int start;
+ int end;
+ int size;
+} FrameRingBuffer;
+
+static int ring_init(FrameRingBuffer **ring, unsigned int capacity, int size)
+{
+ *ring = av_malloc(sizeof(FrameRingBuffer));
+ if (!*ring)
+ return AVERROR(ENOMEM);
+
+ (*ring)->extended_data_buffer = av_malloc_array(capacity, size);
+
+ if (!(*ring)->extended_data_buffer)
+ return AVERROR(ENOMEM);
+
+ (*ring)->capacity = capacity;
+ (*ring)->start = 0;
+ (*ring)->end = 0;
+ (*ring)->size = 0;
+
+ return 0;
+}
+
+static int ring_empty(FrameRingBuffer *ring)
+{
+ return ring->size == 0;
+}
+
+static int ring_full(FrameRingBuffer *ring)
+{
+ return ring->size == ring->capacity;
+}
+
+static int ring_insert(FrameRingBuffer **sample_buffers, AVFrame *frame, AVFilterLink *inlink)
+{
+ uint8_t *dst;
+
+ for (int c = 0; c < inlink->ch_layout.nb_channels; c++) {
+ for (int i = 0; i < frame->nb_samples; i++) {
+ if (ring_full(sample_buffers[c]))
+ return AVERROR(EPERM);
+
+ dst = sample_buffers[c]->extended_data_buffer +
+ sample_buffers[c]->end * av_get_bytes_per_sample(inlink->format);
+
+ sample_buffers[c]->end = (sample_buffers[c]->end + 1) % sample_buffers[c]->capacity;
+ sample_buffers[c]->size++;
+
+ memcpy(dst, frame->extended_data[c] + i * av_get_bytes_per_sample(inlink->format),
+ av_get_bytes_per_sample(inlink->format));
+ }
+ }
+
+ return 0;
+}
+
+static int ring_remove(FrameRingBuffer **sample_buffers, AVFilterLink *inlink, uint8_t **dest, int nb_samples)
+{
+ uint8_t *src;
+
+ for (int c = 0; c < inlink->ch_layout.nb_channels; c++) {
+ for (int i = 0; i < nb_samples; i++) {
+ if (ring_empty(sample_buffers[c]))
+ return AVERROR(EPERM);
+
+ src = sample_buffers[c]->extended_data_buffer +
+ sample_buffers[c]->start * av_get_bytes_per_sample(inlink->format);
+
+ sample_buffers[c]->start = (sample_buffers[c]->start + 1) % sample_buffers[c]->capacity;
+ sample_buffers[c]->size--;
+
+ memcpy(dest[c] + i * av_get_bytes_per_sample(inlink->format), src,
+ av_get_bytes_per_sample(inlink->format));
+ }
+ }
+
+ return 0;
+}
+
+static void ring_free(FrameRingBuffer *ring)
+{
+ av_freep(&ring->extended_data_buffer);
+ av_freep(&ring);
+}
+
+typedef struct AOverlayContext {
+ const AVClass *class;
+ AVFrame *main_input;
+ AVFrame *overlay_input;
+ int64_t pts;
+ int main_eof;
+ int overlay_eof;
+
+ int default_mode;
+ int previous_samples;
+ int64_t pts_gap;
+ int64_t previous_pts;
+ int64_t pts_gap_start;
+ int64_t pts_gap_end;
+
+ int is_disabled;
+ int nb_channels;
+ int crossfade_ready;
+ FrameRingBuffer **main_sample_buffers;
+ FrameRingBuffer **overlay_sample_buffers;
+ int64_t cf_duration;
+ int64_t cf_samples;
+ void (*crossfade_samples)(uint8_t **dst, uint8_t * const *cf0,
+ uint8_t * const *cf1,
+ int nb_samples, int channels);
+
+ int64_t transition_pts;
+ int64_t transition_pts2;
+
+ uint8_t **cf0;
+ uint8_t **cf1;
+} AOverlayContext;
+
+#define SEGMENT_SIZE 1024
+
+#define OFFSET(x) offsetof(AOverlayContext, x)
+
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption aoverlay_options[] = {
+ { "cf_duration", "set duration (in seconds) for cross fade between the inputs", OFFSET(cf_duration), AV_OPT_TYPE_DURATION, {.i64 = 100000}, 0, 60000000, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(aoverlay);
+
+#define CROSSFADE_PLANAR(name, type) \
+static void crossfade_samples_## name ##p(uint8_t **dst, uint8_t * const *cf0, \
+ uint8_t * const *cf1, \
+ int nb_samples, int channels) \
+{ \
+ for (int i = 0; i < nb_samples; i++) { \
+ double main_gain = av_clipd(1.0 * (nb_samples - 1 - i) / nb_samples, 0, 1.); \
+ double overlay_gain = av_clipd(1.0 * i / nb_samples, 0, 1.); \
+ for (int c = 0; c < channels; c++) { \
+ type *d = (type *)dst[c]; \
+ const type *s0 = (type *)cf0[c]; \
+ const type *s1 = (type *)cf1[c]; \
+ \
+ d[i] = s0[i] * main_gain + s1[i] * overlay_gain; \
+ } \
+ } \
+}
+
+CROSSFADE_PLANAR(dbl, double)
+CROSSFADE_PLANAR(flt, float)
+CROSSFADE_PLANAR(s16, int16_t)
+CROSSFADE_PLANAR(s32, int32_t)
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ AOverlayContext *s = ctx->priv;
+
+ s->is_disabled = 1;
+ s->transition_pts = AV_NOPTS_VALUE;
+ s->transition_pts2 = AV_NOPTS_VALUE;
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ AOverlayContext *s = ctx->priv;
+
+ for (int i = 0; i < s->nb_channels; i++) {
+ ring_free(s->main_sample_buffers[i]);
+ ring_free(s->overlay_sample_buffers[i]);
+ av_freep(&s->cf0[i]);
+ av_freep(&s->cf1[i]);
+ }
+ av_freep(&s->cf0);
+ av_freep(&s->cf1);
+
+ av_freep(&s->main_sample_buffers);
+ av_freep(&s->overlay_sample_buffers);
+
+ av_frame_free(&s->main_input);
+ av_frame_free(&s->overlay_input);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVSampleFormat sample_fmts[] = {
+ AV_SAMPLE_FMT_DBLP, AV_SAMPLE_FMT_FLTP,
+ AV_SAMPLE_FMT_S16P, AV_SAMPLE_FMT_S32P,
+ AV_SAMPLE_FMT_NONE
+ };
+
+ return ff_set_common_formats_from_list(ctx, sample_fmts);
+}
+
+static int crossfade_prepare(AOverlayContext *s, AVFilterLink *main_inlink, AVFilterLink *overlay_inlink, AVFilterLink *outlink,
+ int nb_samples, AVFrame **main_buffer, AVFrame **overlay_buffer, int mode)
+{
+ int ret;
+
+ *main_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!(*main_buffer))
+ return AVERROR(ENOMEM);
+
+ (*main_buffer)->pts = s->pts;
+ s->pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+
+ if (ret = ring_remove(s->main_sample_buffers, main_inlink, (*main_buffer)->extended_data, nb_samples) < 0)
+ return ret;
+
+ if (mode == 1) {
+ s->previous_samples = (*main_buffer)->nb_samples;
+ } else if (mode == -1 || (mode == 0 && s->is_disabled)) {
+ *overlay_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!(*overlay_buffer))
+ return AVERROR(ENOMEM);
+
+ if (ret = ring_remove(s->overlay_sample_buffers, overlay_inlink, (*overlay_buffer)->extended_data, nb_samples) < 0)
+ return ret;
+
+ (*overlay_buffer)->pts = (*main_buffer)->pts;
+ }
+
+ s->crossfade_ready = 1;
+
+ return 0;
+}
+
+static int crossfade_samples(AOverlayContext *s, AVFilterLink *main_inlink, AVFilterLink *overlay_inlink, AVFilterLink *outlink,
+ int nb_samples, AVFrame **out, int mode)
+{
+ int ret;
+
+ *out = ff_get_audio_buffer(outlink, nb_samples);
+ if (!(*out))
+ return AVERROR(ENOMEM);
+
+ if (ret = ring_remove(s->main_sample_buffers, main_inlink, s->cf0, nb_samples) < 0)
+ return ret;
+ if (ret = ring_remove(s->overlay_sample_buffers, overlay_inlink, s->cf1, nb_samples) < 0)
+ return ret;
+
+ if (mode == 0) {
+ s->is_disabled ? s->crossfade_samples((*out)->extended_data, s->cf1, s->cf0, nb_samples, (*out)->ch_layout.nb_channels)
+ : s->crossfade_samples((*out)->extended_data, s->cf0, s->cf1, nb_samples, (*out)->ch_layout.nb_channels);
+ } else if (mode == -1) {
+ s->crossfade_samples((*out)->extended_data, s->cf1, s->cf0, s->cf_samples, (*out)->ch_layout.nb_channels);
+ } else if (mode == 1) {
+ s->transition_pts2 != AV_NOPTS_VALUE ? s->crossfade_samples((*out)->extended_data, s->cf1, s->cf0, nb_samples, (*out)->ch_layout.nb_channels)
+ : s->crossfade_samples((*out)->extended_data, s->cf0, s->cf1, nb_samples, (*out)->ch_layout.nb_channels);
+ }
+
+ (*out)->pts = s->pts;
+ s->pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+ s->transition_pts = AV_NOPTS_VALUE;
+ s->transition_pts2 = AV_NOPTS_VALUE;
+ s->crossfade_ready = 0;
+
+ return 0;
+}
+
+static int consume_samples(AOverlayContext *s, AVFilterLink *overlay_inlink, AVFilterLink *outlink)
+{
+ int ret, status, nb_samples;
+ int64_t pts;
+
+ nb_samples = FFMIN(SEGMENT_SIZE, s->overlay_sample_buffers[0]->capacity - s->overlay_sample_buffers[0]->size);
+
+ ret = ff_inlink_consume_samples(overlay_inlink, nb_samples, nb_samples, &s->overlay_input);
+ if (ret < 0) {
+ return ret;
+ } else if (ff_inlink_acknowledge_status(overlay_inlink, &status, &pts)) {
+ s->overlay_eof = 1;
+ return 0;
+ } else if (!ret) {
+ if (ff_outlink_frame_wanted(outlink))
+ ff_inlink_request_frame(overlay_inlink);
+ return 0;
+ }
+
+ if (ret = ring_insert(s->overlay_sample_buffers, s->overlay_input, overlay_inlink) < 0)
+ return ret;
+
+ return 1;
+}
+
+static int activate(AVFilterContext *ctx)
+{
+ AOverlayContext *s = ctx->priv;
+ int status, ret, nb_samples;
+ int64_t pts;
+ AVFrame *out = NULL, *main_buffer = NULL, *overlay_buffer = NULL;
+
+ AVFilterLink *main_inlink = ctx->inputs[0];
+ AVFilterLink *overlay_inlink = ctx->inputs[1];
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ FF_FILTER_FORWARD_STATUS_BACK_ALL(outlink, ctx);
+
+ if (s->default_mode && (s->pts_gap_end - s->pts_gap_start <= 0 || s->overlay_eof)) {
+ s->default_mode = 0;
+ s->transition_pts2 = s->pts_gap_end;
+ }
+
+ if (s->main_sample_buffers[0]->size != s->main_sample_buffers[0]->capacity && !s->main_eof && !s->default_mode) {
+ nb_samples = FFMIN(SEGMENT_SIZE, s->main_sample_buffers[0]->capacity - s->main_sample_buffers[0]->size);
+
+ ret = ff_inlink_consume_samples(main_inlink, nb_samples, nb_samples, &s->main_input);
+ if (ret > 0) {
+ if (ctx->enable_str && s->is_disabled != ctx->is_disabled && !s->overlay_eof) {
+ s->is_disabled = ctx->is_disabled;
+ s->transition_pts = s->main_input->pts;
+
+ if (s->main_sample_buffers[0]->size + s->main_input->nb_samples < s->main_sample_buffers[0]->capacity)
+ s->crossfade_ready = 1;
+ if (s->main_sample_buffers[0]->size == 0) {
+ s->transition_pts = AV_NOPTS_VALUE;
+ s->crossfade_ready = 0;
+ }
+ }
+ if (!ctx->enable_str && !s->default_mode) {
+ if (s->previous_pts + av_rescale_q(s->previous_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base) >= s->main_input->pts) {
+ s->default_mode = 0;
+ s->previous_pts = s->main_input->pts;
+ s->previous_samples = s->main_input->nb_samples;
+ } else if (!s->overlay_eof) {
+ s->pts_gap_start = s->previous_pts;
+ if (s->pts > 0 || s->main_sample_buffers[0]->size > 0)
+ s->transition_pts = s->pts_gap_start;
+ s->pts_gap_end = s->main_input->pts;
+ s->default_mode = 1;
+ }
+ }
+
+ if (ret = ring_insert(s->main_sample_buffers, s->main_input, main_inlink) < 0)
+ return ret;
+ } else if (ret < 0) {
+ return ret;
+ } else if (ff_inlink_acknowledge_status(main_inlink, &status, &pts)) {
+ s->main_eof = 1;
+ s->crossfade_ready = 1;
+ } else if (!ret) {
+ if (ff_outlink_frame_wanted(outlink))
+ ff_inlink_request_frame(main_inlink);
+ return 0;
+ }
+ }
+
+ if (s->main_eof && s->main_sample_buffers[0]->size == 0 && ff_inlink_acknowledge_status(main_inlink, &status, &pts)) {
+ ff_outlink_set_status(outlink, status, pts);
+ return 0;
+ }
+
+ if (s->main_sample_buffers[0]->size < s->main_sample_buffers[0]->capacity &&
+ (s->transition_pts == AV_NOPTS_VALUE || s->main_sample_buffers[0]->size != s->cf_samples) && !s->default_mode) {
+ if (ff_inlink_acknowledge_status(main_inlink, &status, &pts)) {
+ s->main_eof = 1;
+ s->crossfade_ready = 1;
+ } else {
+ ff_inlink_request_frame(main_inlink);
+ return 0;
+ }
+ }
+
+ if (!s->overlay_eof) {
+ if (s->overlay_sample_buffers[0]->size < s->overlay_sample_buffers[0]->capacity) {
+ ret = consume_samples(s, overlay_inlink, outlink);
+ if (ret <= 0) {
+ if (!s->overlay_eof)
+ return ret;
+ }
+ }
+
+ if (s->overlay_sample_buffers[0]->size < s->overlay_sample_buffers[0]->capacity) {
+ if (ff_inlink_acknowledge_status(overlay_inlink, &status, &pts)) {
+ s->overlay_eof = 1;
+ s->transition_pts = s->pts + av_rescale_q(s->overlay_sample_buffers[0]->size - (s->cf_samples / 2),
+ (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+ s->is_disabled = 1;
+ } else {
+ ff_inlink_request_frame(overlay_inlink);
+ return 0;
+ }
+ }
+ }
+
+ if (!ctx->enable_str) {
+ if (s->transition_pts != AV_NOPTS_VALUE && s->main_sample_buffers[0]->size > s->cf_samples + SEGMENT_SIZE) {
+ nb_samples = s->main_sample_buffers[0]->capacity - s->cf_samples - SEGMENT_SIZE;
+
+ if (ret = crossfade_prepare(s, main_inlink, overlay_inlink, outlink, nb_samples, &main_buffer, &overlay_buffer, 1) < 0)
+ return ret;
+
+ return ff_filter_frame(outlink, main_buffer);
+ } else if (s->transition_pts != AV_NOPTS_VALUE || s->transition_pts2 != AV_NOPTS_VALUE) {
+ nb_samples = FFMIN(s->cf_samples, s->main_sample_buffers[0]->size - SEGMENT_SIZE);
+
+ if (ret = crossfade_samples(s, main_inlink, overlay_inlink, outlink, nb_samples, &out, 1) < 0)
+ return ret;
+
+ return ff_filter_frame(outlink, out);
+ } else if (!s->default_mode) {
+ nb_samples = FFMIN(s->main_sample_buffers[0]->size, SEGMENT_SIZE);
+
+ main_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!main_buffer)
+ return AVERROR(ENOMEM);
+
+ main_buffer->pts = s->pts;
+ s->pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+
+ if (ret = ring_remove(s->main_sample_buffers, main_inlink, main_buffer->extended_data, nb_samples) < 0)
+ return ret;
+ }
+
+ if (!s->default_mode || s->overlay_eof) {
+ s->previous_samples = main_buffer->nb_samples;
+ return ff_filter_frame(outlink, main_buffer);
+ }
+
+ s->pts_gap = s->pts_gap_end - s->pts_gap_start;
+
+ nb_samples = FFMIN(SEGMENT_SIZE, av_rescale_q(s->pts_gap, outlink->time_base, (AVRational){ 1, outlink->sample_rate }));
+
+ overlay_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!overlay_buffer)
+ return AVERROR(ENOMEM);
+
+ if (ret = ring_remove(s->overlay_sample_buffers, overlay_inlink, overlay_buffer->extended_data, nb_samples) < 0)
+ return ret;
+
+ s->previous_samples = nb_samples;
+ s->previous_pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+ s->pts_gap_start += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+
+ overlay_buffer->pts = s->pts;
+ s->pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+
+ av_frame_free(&main_buffer);
+
+ return ff_filter_frame(outlink, overlay_buffer);
+ }
+
+ if (s->overlay_eof && s->overlay_sample_buffers[0]->size > 0) {
+ if (s->overlay_sample_buffers[0]->size != s->cf_samples) {
+ nb_samples = s->overlay_sample_buffers[0]->size - s->cf_samples;
+
+ if (ret = crossfade_prepare(s, main_inlink, overlay_inlink, outlink, nb_samples, &main_buffer, &overlay_buffer, -1) < 0)
+ return ret;
+
+ return ff_filter_frame(outlink, overlay_buffer);
+ } else if (s->overlay_sample_buffers[0]->size == s->cf_samples) {
+ if (ret = crossfade_samples(s, main_inlink, overlay_inlink, outlink, s->cf_samples, &out, -1) < 0)
+ return ret;
+
+ return ff_filter_frame(outlink, out);
+ }
+ }
+
+ if (s->transition_pts != AV_NOPTS_VALUE && !s->crossfade_ready) {
+ nb_samples = av_rescale_q(s->transition_pts - (s->cf_samples / 2) - s->pts, outlink->time_base, (AVRational) { 1, outlink->sample_rate });
+
+ if (ret = crossfade_prepare(s, main_inlink, overlay_inlink, outlink, nb_samples, &main_buffer, &overlay_buffer, 0) < 0)
+ return ret;
+ } else if (s->transition_pts != AV_NOPTS_VALUE) {
+ nb_samples = s->main_eof ? s->main_sample_buffers[0]->size : s->cf_samples;
+ if (s->transition_pts < av_rescale_q(s->cf_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base)) {
+ nb_samples = av_rescale_q(s->transition_pts, outlink->time_base, (AVRational){ 1, outlink->sample_rate });
+ }
+
+ if (ret = crossfade_samples(s, main_inlink, overlay_inlink, outlink, nb_samples, &out, 0) < 0)
+ return ret;
+
+ return ff_filter_frame(outlink, out);
+ } else {
+ nb_samples = FFMIN(s->main_sample_buffers[0]->size, SEGMENT_SIZE);
+ main_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!main_buffer)
+ return AVERROR(ENOMEM);
+
+ main_buffer->pts = s->pts;
+ s->pts += av_rescale_q(nb_samples, (AVRational){ 1, outlink->sample_rate }, outlink->time_base);
+
+ if (ret = ring_remove(s->main_sample_buffers, main_inlink, main_buffer->extended_data, nb_samples) < 0)
+ return ret;
+ }
+
+ if (!ff_inlink_evaluate_timeline_at_frame(main_inlink, main_buffer) || (s->overlay_eof && s->overlay_sample_buffers[0]->size == 0)) {
+ return ff_filter_frame(outlink, main_buffer);
+ } else {
+ if (s->transition_pts == AV_NOPTS_VALUE) {
+ nb_samples = FFMIN(s->overlay_sample_buffers[0]->size, SEGMENT_SIZE);
+ overlay_buffer = ff_get_audio_buffer(outlink, nb_samples);
+ if (!overlay_buffer)
+ return AVERROR(ENOMEM);
+ if (ret = ring_remove(s->overlay_sample_buffers, overlay_inlink, overlay_buffer->extended_data, nb_samples) < 0)
+ return ret;
+
+ overlay_buffer->pts = main_buffer->pts;
+ }
+ av_frame_free(&main_buffer);
+ return ff_filter_frame(outlink, overlay_buffer);
+ }
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AOverlayContext *s = ctx->priv;
+ int ret, size, ring_buffer_size;
+
+ switch (outlink->format) {
+ case AV_SAMPLE_FMT_DBLP: s->crossfade_samples = crossfade_samples_dblp;
+ size = sizeof(double);
+ break;
+ case AV_SAMPLE_FMT_FLTP: s->crossfade_samples = crossfade_samples_fltp;
+ size = sizeof(float);
+ break;
+ case AV_SAMPLE_FMT_S16P: s->crossfade_samples = crossfade_samples_s16p;
+ size = sizeof(int16_t);
+ break;
+ case AV_SAMPLE_FMT_S32P: s->crossfade_samples = crossfade_samples_s32p;
+ size = sizeof(int32_t);
+ break;
+ }
+
+ if (s->cf_duration)
+ s->cf_samples = av_rescale(s->cf_duration, outlink->sample_rate, AV_TIME_BASE);
+ else
+ s->cf_samples = av_rescale(100000, outlink->sample_rate, AV_TIME_BASE);
+
+ s->nb_channels = outlink->ch_layout.nb_channels;
+
+ s->cf0 = av_malloc_array(s->nb_channels, sizeof(uint8_t*));
+ s->cf1 = av_malloc_array(s->nb_channels, sizeof(uint8_t*));
+
+ ring_buffer_size = SEGMENT_SIZE + SEGMENT_SIZE * (1 + ((s->cf_samples - 1) / SEGMENT_SIZE));
+
+ s->main_sample_buffers = av_malloc_array(s->nb_channels, sizeof(FrameRingBuffer*));
+ for (int i = 0; i < s->nb_channels; i++) {
+ s->cf0[i] = av_malloc_array(s->cf_samples, size);
+ ret = ring_init(&s->main_sample_buffers[i], ring_buffer_size, size);
+ if (ret < 0)
+ return ret;
+ }
+
+ s->overlay_sample_buffers = av_malloc_array(s->nb_channels, sizeof(FrameRingBuffer*));
+ for (int i = 0; i < s->nb_channels; i++) {
+ s->cf1[i] = av_malloc_array(s->cf_samples, size);
+ ret = ring_init(&s->overlay_sample_buffers[i], ring_buffer_size, size);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static const AVFilterPad avfilter_af_aoverlay_inputs[] = {
+ {
+ .name = "main",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+ {
+ .name = "s->overlay_input",
+ .type = AVMEDIA_TYPE_AUDIO,
+ },
+};
+
+static const AVFilterPad avfilter_af_aoverlay_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_output,
+ },
+};
+
+const AVFilter ff_af_aoverlay = {
+ .name = "aoverlay",
+ .description = NULL_IF_CONFIG_SMALL("Replace a specified section of an audio stream with another audio input."),
+ .priv_size = sizeof(AOverlayContext),
+ .priv_class = &aoverlay_class,
+ .activate = activate,
+ .init = init,
+ .uninit = uninit,
+ FILTER_INPUTS(avfilter_af_aoverlay_inputs),
+ FILTER_OUTPUTS(avfilter_af_aoverlay_outputs),
+ FILTER_QUERY_FUNC(query_formats),
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index d4184d6e808..abdeb40fb49 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -66,6 +66,7 @@ extern const AVFilter ff_af_anlmdn;
extern const AVFilter ff_af_anlmf;
extern const AVFilter ff_af_anlms;
extern const AVFilter ff_af_anull;
+extern const AVFilter ff_af_aoverlay;
extern const AVFilter ff_af_apad;
extern const AVFilter ff_af_aperms;
extern const AVFilter ff_af_aphaser;
--
2.39.3 (Apple Git-145)
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