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lavfi/avf_showspectrum: use automatic framing. 

The framework can ensure that each input frame has exactly
the correct number of samples, except the last one.
This commit is contained in:
Nicolas George 2014-08-03 16:58:27 +02:00
parent d4de6d4fad
commit ec33df6045
1 changed files with 17 additions and 31 deletions
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48
libavfilter/avf_showspectrum.c
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@ -55,8 +55,6 @@ typedef struct {
RDFTContext *rdft; ///< Real Discrete Fourier Transform context
int rdft_bits; ///< number of bits (RDFT window size = 1<<rdft_bits)
FFTSample **rdft_data; ///< bins holder for each (displayed) channels
int filled; ///< number of samples (per channel) filled in current rdft_buffer
int consumed; ///< number of samples (per channel) consumed from the input frame
float *window_func_lut; ///< Window function LUT
enum WindowFunc win_func;
float *combine_buffer; ///< color combining buffer (3 * h items)
@ -199,7 +197,6 @@ static int config_output(AVFilterLink *outlink)
if (!s->rdft_data[i])
return AVERROR(ENOMEM);
}
s->filled = 0;
/* pre-calc windowing function */
s->window_func_lut =
@ -248,6 +245,9 @@ static int config_output(AVFilterLink *outlink)
outlink->frame_rate = av_make_q(inlink->sample_rate, win_size);
inlink->min_samples = inlink->max_samples = inlink->partial_buf_size =
win_size;
s->combine_buffer =
av_realloc_f(s->combine_buffer, outlink->h * 3,
sizeof(*s->combine_buffer));
@ -264,7 +264,6 @@ inline static int push_frame(AVFilterLink *outlink)
s->xpos++;
if (s->xpos >= outlink->w)
s->xpos = 0;
s->filled = 0;
s->req_fullfilled = 1;
return ff_filter_frame(outlink, av_frame_clone(s->outpicref));
@ -284,7 +283,7 @@ static int request_frame(AVFilterLink *outlink)
return ret;
}
static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples, int nb_samples)
static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples)
{
int ret;
AVFilterContext *ctx = inlink->dst;
@ -297,26 +296,21 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples, int nb
const int nb_freq = 1 << (s->rdft_bits - 1);
const int win_size = nb_freq << 1;
const double w = 1. / (sqrt(nb_freq) * 32768.);
int h = s->channel_height;
int ch, plane, n, y;
const int start = s->filled;
const int add_samples = FFMIN(win_size - start, nb_samples);
av_assert0(insamples->nb_samples == win_size);
/* fill RDFT input with the number of samples available */
for (ch = 0; ch < s->nb_display_channels; ch++) {
const int16_t *p = (int16_t *)insamples->extended_data[ch];
p += s->consumed;
for (n = 0; n < add_samples; n++)
s->rdft_data[ch][start + n] = p[n] * s->window_func_lut[start + n];
for (n = 0; n < win_size; n++)
s->rdft_data[ch][n] = p[n] * s->window_func_lut[n];
}
s->filled += add_samples;
/* complete RDFT window size? */
if (s->filled == win_size) {
/* channel height */
int h = s->channel_height;
/* TODO reindent */
/* run RDFT on each samples set */
for (ch = 0; ch < s->nb_display_channels; ch++)
@ -465,32 +459,24 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples, int nb
}
}
outpicref->pts = insamples->pts +
av_rescale_q(s->consumed + add_samples - win_size,
(AVRational){ 1, inlink->sample_rate },
outlink->time_base);
outpicref->pts = insamples->pts;
ret = push_frame(outlink);
if (ret < 0)
return ret;
}
return add_samples;
return win_size;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
AVFilterContext *ctx = inlink->dst;
ShowSpectrumContext *s = ctx->priv;
int ret = 0, left_samples = insamples->nb_samples;
unsigned win_size = 1 << s->rdft_bits;
int ret = 0;
s->consumed = 0;
while (left_samples) {
int ret = plot_spectrum_column(inlink, insamples, left_samples);
if (ret < 0)
break;
s->consumed += ret;
left_samples -= ret;
}
av_assert0(insamples->nb_samples <= win_size);
if (insamples->nb_samples == win_size)
ret = plot_spectrum_column(inlink, insamples);
av_frame_free(&insamples);
return ret;