[FFmpeg-devel] [PATCH 2/3] avfilter/showwaves: split out draw sample code.
Clément Bœsch
u at pkh.me
Tue Aug 19 14:47:03 CEST 2014
From: Clément Bœsch <clement at stupeflix.com>
---
libavfilter/avf_showwaves.c | 119 +++++++++++++++++++++++++++-----------------
1 file changed, 74 insertions(+), 45 deletions(-)
diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
index e4911cc..1389e64 100644
--- a/libavfilter/avf_showwaves.c
+++ b/libavfilter/avf_showwaves.c
@@ -51,6 +51,8 @@ typedef struct {
int n;
int sample_count_mod;
enum ShowWavesMode mode;
+ void (*draw_sample)(uint8_t *buf, int height, int linesize,
+ int16_t sample, int16_t *prev_y, int intensity);
} ShowWavesContext;
#define OFFSET(x) offsetof(ShowWavesContext, x)
@@ -176,6 +178,57 @@ static int request_frame(AVFilterLink *outlink)
#define MAX_INT16 ((1<<15) -1)
+static void draw_sample_point(uint8_t *buf, int height, int linesize,
+ int16_t sample, int16_t *prev_y, int intensity)
+{
+ const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
+ if (h >= 0 && h < height)
+ buf[h * linesize] += intensity;
+}
+
+static void draw_sample_line(uint8_t *buf, int height, int linesize,
+ int16_t sample, int16_t *prev_y, int intensity)
+{
+ int k;
+ const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
+ int start = height/2;
+ int end = av_clip(h, 0, height-1);
+ if (start > end)
+ FFSWAP(int16_t, start, end);
+ for (k = start; k < end; k++)
+ buf[k * linesize] += intensity;
+}
+
+static void draw_sample_p2p(uint8_t *buf, int height, int linesize,
+ int16_t sample, int16_t *prev_y, int intensity)
+{
+ int k;
+ const int h = height/2 - av_rescale(sample, height/2, MAX_INT16);
+ if (h >= 0 && h < height) {
+ buf[h * linesize] += intensity;
+ if (*prev_y && h != *prev_y) {
+ int start = *prev_y;
+ int end = av_clip(h, 0, height-1);
+ if (start > end)
+ FFSWAP(int16_t, start, end);
+ for (k = start + 1; k < end; k++)
+ buf[k * linesize] += intensity;
+ }
+ }
+ *prev_y = h;
+}
+
+static void draw_sample_center(uint8_t *buf, int height, int linesize,
+ int16_t sample, int16_t *prev_y, int intensity)
+{
+ int k;
+ const int h = av_rescale(abs(sample), height, UINT16_MAX);
+ const int start = (height - h) / 2;
+ const int end = start + h;
+ for (k = start; k < end; k++)
+ buf[k * linesize] += intensity;
+}
+
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
AVFilterContext *ctx = inlink->dst;
@@ -186,7 +239,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
int linesize = outpicref ? outpicref->linesize[0] : 0;
int16_t *p = (int16_t *)insamples->data[0];
int nb_channels = inlink->channels;
- int i, j, k, h, ret = 0;
+ int i, j, ret = 0;
const int n = showwaves->n;
const int x = 255 / (nb_channels * n); /* multiplication factor, pre-computed to avoid in-loop divisions */
@@ -207,50 +260,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
for (j = 0; j < outlink->h; j++)
memset(outpicref->data[0] + j * linesize, 0, outlink->w);
}
- for (j = 0; j < nb_channels; j++) {
- int start, end;
- switch (showwaves->mode) {
- case MODE_POINT:
- h = showwaves->h/2 - av_rescale(*p++, showwaves->h/2, MAX_INT16);
- if (h >= 0 && h < outlink->h)
- *(outpicref->data[0] + showwaves->buf_idx + h * linesize) += x;
- break;
-
- case MODE_LINE:
- h = showwaves->h/2 - av_rescale(*p++, showwaves->h/2, MAX_INT16);
- start = showwaves->h/2;
- end = av_clip(h, 0, outlink->h-1);
- if (start > end) FFSWAP(int16_t, start, end);
- for (k = start; k < end; k++)
- *(outpicref->data[0] + showwaves->buf_idx + k * linesize) += x;
- break;
-
- case MODE_P2P:
- h = showwaves->h/2 - av_rescale(*p++, showwaves->h/2, MAX_INT16);
- if (h >= 0 && h < outlink->h) {
- *(outpicref->data[0] + showwaves->buf_idx + h * linesize) += x;
- if (showwaves->buf_idy[j] && h != showwaves->buf_idy[j]) {
- start = showwaves->buf_idy[j];
- end = av_clip(h, 0, outlink->h-1);
- if (start > end)
- FFSWAP(int16_t, start, end);
- for (k = start + 1; k < end; k++)
- *(outpicref->data[0] + showwaves->buf_idx + k * linesize) += x;
- }
- }
- break;
-
- case MODE_CENTER:
- h = av_rescale(abs(*p++), showwaves->h, UINT16_MAX);
- start = (showwaves->h - h) / 2;
- end = start + h;
- for (k = start; k < end; k++)
- *(outpicref->data[0] + showwaves->buf_idx + k * linesize) += x;
- break;
- }
- /* store current y coordinate for this channel */
- showwaves->buf_idy[j] = h;
- }
+ for (j = 0; j < nb_channels; j++)
+ showwaves->draw_sample(outpicref->data[0] + showwaves->buf_idx,
+ outlink->h, linesize, *p++,
+ &showwaves->buf_idy[j], x);
showwaves->sample_count_mod++;
if (showwaves->sample_count_mod == n) {
@@ -267,6 +280,21 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
return ret;
}
+static av_cold int init(AVFilterContext *ctx)
+{
+ ShowWavesContext *showwaves = ctx->priv;
+
+ switch (showwaves->mode) {
+ case MODE_POINT: showwaves->draw_sample = draw_sample_point; break;
+ case MODE_LINE: showwaves->draw_sample = draw_sample_line; break;
+ case MODE_P2P: showwaves->draw_sample = draw_sample_p2p; break;
+ case MODE_CENTER: showwaves->draw_sample = draw_sample_center; break;
+ default:
+ return AVERROR_BUG;
+ }
+ return 0;
+}
+
static const AVFilterPad showwaves_inputs[] = {
{
.name = "default",
@@ -289,6 +317,7 @@ static const AVFilterPad showwaves_outputs[] = {
AVFilter ff_avf_showwaves = {
.name = "showwaves",
.description = NULL_IF_CONFIG_SMALL("Convert input audio to a video output."),
+ .init = init,
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(ShowWavesContext),
--
2.0.4
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