[FFmpeg-devel] [PATCH] avfilter/showwaves: add single_pic option
Clément Bœsch
u at pkh.me
Wed Dec 24 15:03:26 CET 2014
TODO: bump minor
---
doc/filters.texi | 12 +++
libavfilter/avf_showwaves.c | 175 +++++++++++++++++++++++++++++++++++++++-----
2 files changed, 169 insertions(+), 18 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 7fac8fb..7953e62 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -11334,6 +11334,11 @@ option @var{n}. Default value is "25".
@item split_channels
Set if channels should be drawn separately or overlap. Default value is 0.
+ at item single_pic
+Output only one frame at the end if set. This option can only work with
+ at option{mode}=@var{cline}. Note that this option will store the whole decoded
+audio track in memory. Default value is 0.
+
@end table
@subsection Examples
@@ -11352,6 +11357,13 @@ frame rate of 30 frames per second:
@example
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
@end example
+
+ at item
+Extract a channel split representation of the wave form of a whole audio track
+in a 1024x800 picture using @command{ffmpeg}:
+ at example
+ffmpeg -i audio.flac -lavfi showwaves=split_channels=1:single_pic=1:s=1024x800 waveform.png
+ at end example
@end itemize
@section split, asplit
diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
index fa34a52..341f8ec 100644
--- a/libavfilter/avf_showwaves.c
+++ b/libavfilter/avf_showwaves.c
@@ -23,6 +23,7 @@
* audio to video multimedia filter
*/
+#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
@@ -40,6 +41,11 @@ enum ShowWavesMode {
MODE_NB,
};
+struct frame_node {
+ AVFrame *frame;
+ struct frame_node *next;
+};
+
typedef struct {
const AVClass *class;
int w, h;
@@ -54,6 +60,13 @@ typedef struct {
int split_channels;
void (*draw_sample)(uint8_t *buf, int height, int linesize,
int16_t sample, int16_t *prev_y, int intensity);
+
+ /* single picture */
+ int single_pic;
+ struct frame_node *audio_frames;
+ struct frame_node *last_frame;
+ int64_t total_samples;
+ int64_t *sum; /* abs sum of the samples per channel */
} ShowWavesContext;
#define OFFSET(x) offsetof(ShowWavesContext, x)
@@ -71,6 +84,7 @@ static const AVOption showwaves_options[] = {
{ "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
{ "r", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, FLAGS },
{ "split_channels", "draw channels separately", OFFSET(split_channels), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
+ { "single_pic", "draw only one video frame", OFFSET(single_pic), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ NULL }
};
@@ -82,6 +96,20 @@ static av_cold void uninit(AVFilterContext *ctx)
av_frame_free(&showwaves->outpicref);
av_freep(&showwaves->buf_idy);
+
+ if (showwaves->single_pic) {
+ struct frame_node *node = showwaves->audio_frames;
+
+ while (node) {
+ struct frame_node *tmp = node;
+
+ node = node->next;
+ av_frame_free(&tmp->frame);
+ av_freep(&tmp);
+ }
+ av_freep(&showwaves->sum);
+ showwaves->last_frame = NULL;
+ }
}
static int query_formats(AVFilterContext *ctx)
@@ -118,6 +146,20 @@ static int query_formats(AVFilterContext *ctx)
return 0;
}
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ShowWavesContext *showwaves = ctx->priv;
+
+ if (showwaves->single_pic) {
+ showwaves->sum = av_mallocz_array(inlink->channels, sizeof(*showwaves->sum));
+ if (!showwaves->sum)
+ return AVERROR(ENOMEM);
+ }
+
+ return 0;
+}
+
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
@@ -162,6 +204,54 @@ inline static int push_frame(AVFilterLink *outlink)
return ret;
}
+static int push_single_pic(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
+ ShowWavesContext *showwaves = ctx->priv;
+ int64_t n = 0, max_samples = showwaves->total_samples / outlink->w;
+ AVFrame *out = showwaves->outpicref;
+ struct frame_node *node;
+ const int nb_channels = inlink->channels;
+ const int x = 255 / (showwaves->split_channels ? 1 : nb_channels);
+ const int ch_height = showwaves->split_channels ? outlink->h / nb_channels : outlink->h;
+ const int linesize = out->linesize[0];
+ int col = 0;
+ int64_t *sum = showwaves->sum;
+
+ av_log(ctx, AV_LOG_DEBUG, "Create frame averaging %"PRId64" samples per column\n", max_samples);
+
+ memset(sum, 0, nb_channels);
+
+ for (node = showwaves->audio_frames; node; node = node->next) {
+ int i;
+ const AVFrame *frame = node->frame;
+ const int16_t *p = (const int16_t *)frame->data[0];
+
+ for (i = 0; i < frame->nb_samples; i++) {
+ int ch;
+
+ for (ch = 0; ch < nb_channels; ch++)
+ sum[ch] += abs(p[ch + i*nb_channels]) << 1;
+ if (n++ == max_samples) {
+ for (ch = 0; ch < nb_channels; ch++) {
+ int16_t sample = sum[ch] / max_samples;
+ uint8_t *buf = out->data[0] + col;
+ if (showwaves->split_channels)
+ buf += ch*ch_height*linesize;
+ av_assert0(col < outlink->w);
+ showwaves->draw_sample(buf, ch_height, linesize, sample, &showwaves->buf_idy[ch], x);
+ sum[ch] = 0;
+ }
+ col++;
+ n = 0;
+ }
+ }
+ }
+
+ return push_frame(outlink);
+}
+
static int request_frame(AVFilterLink *outlink)
{
ShowWavesContext *showwaves = outlink->src->priv;
@@ -173,8 +263,13 @@ static int request_frame(AVFilterLink *outlink)
ret = ff_request_frame(inlink);
} while (!showwaves->req_fullfilled && ret >= 0);
- if (ret == AVERROR_EOF && showwaves->outpicref)
- push_frame(outlink);
+ if (ret == AVERROR_EOF && showwaves->outpicref) {
+ if (showwaves->single_pic)
+ push_single_pic(outlink);
+ else
+ push_frame(outlink);
+ }
+
return ret;
}
@@ -231,6 +326,27 @@ static void draw_sample_cline(uint8_t *buf, int height, int linesize,
buf[k * linesize] += intensity;
}
+static int alloc_out_frame(ShowWavesContext *showwaves, const int16_t *p,
+ const AVFilterLink *inlink, AVFilterLink *outlink,
+ const AVFrame *in)
+{
+ if (!showwaves->outpicref) {
+ int j;
+ AVFrame *out = showwaves->outpicref =
+ ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out)
+ return AVERROR(ENOMEM);
+ out->width = outlink->w;
+ out->height = outlink->h;
+ out->pts = in->pts + av_rescale_q((p - (int16_t *)in->data[0]) / inlink->channels,
+ av_make_q(1, inlink->sample_rate),
+ outlink->time_base);
+ for (j = 0; j < outlink->h; j++)
+ memset(out->data[0] + j*out->linesize[0], 0, outlink->w);
+ }
+ return 0;
+}
+
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
AVFilterContext *ctx = inlink->dst;
@@ -238,7 +354,6 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
ShowWavesContext *showwaves = ctx->priv;
const int nb_samples = insamples->nb_samples;
AVFrame *outpicref = showwaves->outpicref;
- int linesize = outpicref ? outpicref->linesize[0] : 0;
int16_t *p = (int16_t *)insamples->data[0];
int nb_channels = inlink->channels;
int i, j, ret = 0;
@@ -246,25 +361,44 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
const int x = 255 / ((showwaves->split_channels ? 1 : nb_channels) * n); /* multiplication factor, pre-computed to avoid in-loop divisions */
const int ch_height = showwaves->split_channels ? outlink->h / nb_channels : outlink->h;
+ if (showwaves->single_pic) {
+ struct frame_node *f;
+
+ ret = alloc_out_frame(showwaves, p, inlink, outlink, insamples);
+ if (ret < 0)
+ goto end;
+
+ /* queue the audio frame */
+ f = av_malloc(sizeof(*f));
+ if (!f) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ f->frame = insamples;
+ f->next = NULL;
+ if (!showwaves->last_frame) {
+ showwaves->audio_frames =
+ showwaves->last_frame = f;
+ } else {
+ showwaves->last_frame->next = f;
+ showwaves->last_frame = f;
+ }
+ showwaves->total_samples += insamples->nb_samples;
+
+ return 0;
+ }
+
/* draw data in the buffer */
for (i = 0; i < nb_samples; i++) {
- if (!showwaves->outpicref) {
- showwaves->outpicref = outpicref =
- ff_get_video_buffer(outlink, outlink->w, outlink->h);
- if (!outpicref)
- return AVERROR(ENOMEM);
- outpicref->width = outlink->w;
- outpicref->height = outlink->h;
- outpicref->pts = insamples->pts +
- av_rescale_q((p - (int16_t *)insamples->data[0]) / nb_channels,
- (AVRational){ 1, inlink->sample_rate },
- outlink->time_base);
- linesize = outpicref->linesize[0];
- for (j = 0; j < outlink->h; j++)
- memset(outpicref->data[0] + j * linesize, 0, outlink->w);
- }
+
+ ret = alloc_out_frame(showwaves, p, inlink, outlink, insamples);
+ if (ret < 0)
+ goto end;
+ outpicref = showwaves->outpicref;
+
for (j = 0; j < nb_channels; j++) {
uint8_t *buf = outpicref->data[0] + showwaves->buf_idx;
+ const int linesize = outpicref->linesize[0];
if (showwaves->split_channels)
buf += j*ch_height*linesize;
showwaves->draw_sample(buf, ch_height, linesize, *p++,
@@ -282,6 +416,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
outpicref = showwaves->outpicref;
}
+end:
av_frame_free(&insamples);
return ret;
}
@@ -290,6 +425,9 @@ static av_cold int init(AVFilterContext *ctx)
{
ShowWavesContext *showwaves = ctx->priv;
+ if (showwaves->single_pic)
+ showwaves->mode = MODE_CENTERED_LINE;
+
switch (showwaves->mode) {
case MODE_POINT: showwaves->draw_sample = draw_sample_point; break;
case MODE_LINE: showwaves->draw_sample = draw_sample_line; break;
@@ -305,6 +443,7 @@ static const AVFilterPad showwaves_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
--
2.2.1
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