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resampler: Add support for resamplers that consume less data than asked.

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libsamplerate_resample() assumed that src_process() would
always consume the whole input buffer. That was an invalid
assumption leading to crashes.

This patch adds a leftover memchunk for storing any
non-consumed input. When pa_resampler_run() is called next
time, the leftover is prepended to the new input.

Changes in v3:
 - Make the calculations in pa_resampler_result() and
   pa_resampler_max_block_size() more readable and more
   correct.
 - Rework the leftover storing: instead of using a dedicated
   buffer for it, store it in the beginning of remap_buf.
   This can avoid some memory copying. (The idea was
   suggested by Wang Xingchao.)
 - Use a generic save_leftover() function instead of doing
   the leftover copying in the resampler implementation.
 - Use the leftover logic also with the speex and ffmpeg
   resamplers.
   [ed: dropped the speex bit since the API guarantees that
    it will consume everything -- Arun]

Changes in v2:
 - If add_leftover() is called with zero-length input while
   the leftover length is non-zero, we don't try to acquire
   the input memblock.
 - Instead of taking a reference to the original input in
   libsamplerate_resample(), we copy the leftover data to a
   new memblock. This is done, because otherwise, if the
   input is one of the internal buffers, the data can get
   overwritten before reading it in add_leftover().
 - Store add_leftover_buf size in bytes instead of samples
   (more convenient, but less consistent with other code).

BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=47156
This commit is contained in:
Tanu Kaskinen 2012-05-10 09:19:23 +03:00 • committed by Arun Raghavan
parent 1a75e1c297
commit 1eb7c4a465
1 changed files with 138 additions and 59 deletions
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197
src/pulsecore/resampler.c
View file

@ -61,9 +61,10 @@ struct pa_resampler {
pa_memchunk resample_buf;
pa_memchunk from_work_format_buf;
unsigned to_work_format_buf_samples;
unsigned remap_buf_samples;
size_t remap_buf_size;
unsigned resample_buf_samples;
unsigned from_work_format_buf_samples;
pa_bool_t remap_buf_contains_leftover_data;
pa_sample_format_t work_format;
@ -379,23 +380,39 @@ void pa_resampler_set_output_rate(pa_resampler *r, uint32_t rate) {
size_t pa_resampler_request(pa_resampler *r, size_t out_length) {
pa_assert(r);
/* Let's round up here */
/* Let's round up here to make it more likely that the caller will get at
* least out_length amount of data from pa_resampler_run().
*
* We don't take the leftover into account here. If we did, then it might
* be in theory possible that this function would return 0 and
* pa_resampler_run() would also return 0. That could lead to infinite
* loops. When the leftover is ignored here, such loops would eventually
* terminate, because the leftover would grow each round, finally
* surpassing the minimum input threshold of the resampler. */
return (((((out_length + r->o_fz-1) / r->o_fz) * r->i_ss.rate) + r->o_ss.rate-1) / r->o_ss.rate) * r->i_fz;
}
size_t pa_resampler_result(pa_resampler *r, size_t in_length) {
size_t frames;
pa_assert(r);
/* Let's round up here */
/* Let's round up here to ensure that the caller will always allocate big
* enough output buffer. */
return (((((in_length + r->i_fz-1) / r->i_fz) * r->o_ss.rate) + r->i_ss.rate-1) / r->i_ss.rate) * r->o_fz;
frames = (in_length + r->i_fz - 1) / r->i_fz;
if (r->remap_buf_contains_leftover_data)
frames += r->remap_buf.length / (r->w_sz * r->o_ss.channels);
return ((frames * r->o_ss.rate + r->i_ss.rate - 1) / r->i_ss.rate) * r->o_fz;
}
size_t pa_resampler_max_block_size(pa_resampler *r) {
size_t block_size_max;
pa_sample_spec ss;
size_t fs;
pa_sample_spec max_ss;
size_t max_fs;
size_t frames;
pa_assert(r);
@ -403,17 +420,21 @@ size_t pa_resampler_max_block_size(pa_resampler *r) {
/* We deduce the "largest" sample spec we're using during the
* conversion */
ss.channels = (uint8_t) (PA_MAX(r->i_ss.channels, r->o_ss.channels));
max_ss.channels = (uint8_t) (PA_MAX(r->i_ss.channels, r->o_ss.channels));
/* We silently assume that the format enum is ordered by size */
ss.format = PA_MAX(r->i_ss.format, r->o_ss.format);
ss.format = PA_MAX(ss.format, r->work_format);
max_ss.format = PA_MAX(r->i_ss.format, r->o_ss.format);
max_ss.format = PA_MAX(max_ss.format, r->work_format);
ss.rate = PA_MAX(r->i_ss.rate, r->o_ss.rate);
max_ss.rate = PA_MAX(r->i_ss.rate, r->o_ss.rate);
fs = pa_frame_size(&ss);
max_fs = pa_frame_size(&max_ss);
frames = block_size_max / max_fs - EXTRA_FRAMES;
return (((block_size_max/fs - EXTRA_FRAMES)*r->i_ss.rate)/ss.rate)*r->i_fz;
if (r->remap_buf_contains_leftover_data)
frames -= r->remap_buf.length / (r->w_sz * r->o_ss.channels);
return (frames * r->i_ss.rate / max_ss.rate) * r->i_fz;
}
void pa_resampler_reset(pa_resampler *r) {
@ -421,6 +442,8 @@ void pa_resampler_reset(pa_resampler *r) {
if (r->impl_reset)
r->impl_reset(r);
r->remap_buf_contains_leftover_data = FALSE;
}
pa_resample_method_t pa_resampler_get_method(pa_resampler *r) {
@ -1101,41 +1124,74 @@ static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input)
}
static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) {
unsigned in_n_samples, out_n_samples, n_frames;
unsigned in_n_samples, out_n_samples, in_n_frames, out_n_frames;
void *src, *dst;
pa_remap_t *remap;
size_t leftover_length = 0;
pa_bool_t have_leftover;
pa_assert(r);
pa_assert(input);
pa_assert(input->memblock);
/* Remap channels and place the result in remap_buf. */
/* Remap channels and place the result in remap_buf. There may be leftover
* data in the beginning of remap_buf. The leftover data is already
* remapped, so it's not part of the input, it's part of the output. */
if (!r->map_required || !input->length)
have_leftover = r->remap_buf_contains_leftover_data;
r->remap_buf_contains_leftover_data = FALSE;
if (!have_leftover && (!r->map_required || input->length <= 0))
return input;
else if (input->length <= 0)
return &r->remap_buf;
in_n_samples = (unsigned) (input->length / r->w_sz);
n_frames = in_n_samples / r->i_ss.channels;
out_n_samples = n_frames * r->o_ss.channels;
in_n_frames = out_n_frames = in_n_samples / r->i_ss.channels;
r->remap_buf.index = 0;
r->remap_buf.length = r->w_sz * out_n_samples;
if (!r->remap_buf.memblock || r->remap_buf_samples < out_n_samples) {
if (r->remap_buf.memblock)
pa_memblock_unref(r->remap_buf.memblock);
r->remap_buf_samples = out_n_samples;
r->remap_buf.memblock = pa_memblock_new(r->mempool, r->remap_buf.length);
if (have_leftover) {
leftover_length = r->remap_buf.length;
out_n_frames += leftover_length / (r->w_sz * r->o_ss.channels);
}
src = ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index);
dst = pa_memblock_acquire(r->remap_buf.memblock);
out_n_samples = out_n_frames * r->o_ss.channels;
r->remap_buf.length = out_n_samples * r->w_sz;
remap = &r->remap;
if (have_leftover) {
if (r->remap_buf_size < r->remap_buf.length) {
pa_memblock *new_block = pa_memblock_new(r->mempool, r->remap_buf.length);
pa_assert(remap->do_remap);
remap->do_remap(remap, dst, src, n_frames);
src = pa_memblock_acquire(r->remap_buf.memblock);
dst = pa_memblock_acquire(new_block);
memcpy(dst, src, leftover_length);
pa_memblock_release(r->remap_buf.memblock);
pa_memblock_release(new_block);
pa_memblock_unref(r->remap_buf.memblock);
r->remap_buf.memblock = new_block;
r->remap_buf_size = r->remap_buf.length;
}
} else {
if (!r->remap_buf.memblock || r->remap_buf_size < r->remap_buf.length) {
if (r->remap_buf.memblock)
pa_memblock_unref(r->remap_buf.memblock);
r->remap_buf_size = r->remap_buf.length;
r->remap_buf.memblock = pa_memblock_new(r->mempool, r->remap_buf.length);
}
}
src = (uint8_t *) pa_memblock_acquire(input->memblock) + input->index;
dst = (uint8_t *) pa_memblock_acquire(r->remap_buf.memblock) + leftover_length;
if (r->map_required) {
pa_remap_t *remap = &r->remap;
pa_assert(remap->do_remap);
remap->do_remap(remap, dst, src, in_n_frames);
} else
memcpy(dst, src, input->length);
pa_memblock_release(input->memblock);
pa_memblock_release(r->remap_buf.memblock);
@ -1243,6 +1299,32 @@ void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out)
pa_memchunk_reset(out);
}
static void save_leftover(pa_resampler *r, void *buf, size_t len) {
void *dst;
pa_assert(r);
pa_assert(buf);
pa_assert(len > 0);
/* Store the leftover to remap_buf. */
r->remap_buf.length = len;
if (!r->remap_buf.memblock || r->remap_buf_size < r->remap_buf.length) {
if (r->remap_buf.memblock)
pa_memblock_unref(r->remap_buf.memblock);
r->remap_buf_size = r->remap_buf.length;
r->remap_buf.memblock = pa_memblock_new(r->mempool, r->remap_buf.length);
}
dst = pa_memblock_acquire(r->remap_buf.memblock);
memcpy(dst, buf, r->remap_buf.length);
pa_memblock_release(r->remap_buf.memblock);
r->remap_buf_contains_leftover_data = TRUE;
}
/*** libsamplerate based implementation ***/
#ifdef HAVE_LIBSAMPLERATE
@ -1266,7 +1348,13 @@ static void libsamplerate_resample(pa_resampler *r, const pa_memchunk *input, un
data.end_of_input = 0;
pa_assert_se(src_process(r->src.state, &data) == 0);
pa_assert((unsigned) data.input_frames_used == in_n_frames);
if (data.input_frames_used < in_n_frames) {
void *leftover_data = data.data_in + data.input_frames_used * r->o_ss.channels;
size_t leftover_length = (in_n_frames - data.input_frames_used) * sizeof(float) * r->o_ss.channels;
save_leftover(r, leftover_data, leftover_length);
}
pa_memblock_release(input->memblock);
pa_memblock_release(output->memblock);
@ -1595,6 +1683,7 @@ static int peaks_init(pa_resampler*r) {
static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned in_n_frames, pa_memchunk *output, unsigned *out_n_frames) {
unsigned used_frames = 0, c;
int previous_consumed_frames = -1;
pa_assert(r);
pa_assert(input);
@ -1606,25 +1695,14 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
pa_memblock *b, *w;
int16_t *p, *t, *k, *q, *s;
int consumed_frames;
unsigned in, l;
/* Allocate a new block */
b = pa_memblock_new(r->mempool, r->ffmpeg.buf[c].length + in_n_frames * sizeof(int16_t));
p = pa_memblock_acquire(b);
/* Copy the remaining data into it */
l = (unsigned) r->ffmpeg.buf[c].length;
if (r->ffmpeg.buf[c].memblock) {
t = (int16_t*) ((uint8_t*) pa_memblock_acquire(r->ffmpeg.buf[c].memblock) + r->ffmpeg.buf[c].index);
memcpy(p, t, l);
pa_memblock_release(r->ffmpeg.buf[c].memblock);
pa_memblock_unref(r->ffmpeg.buf[c].memblock);
pa_memchunk_reset(&r->ffmpeg.buf[c]);
}
/* Now append the new data, splitting up channels */
/* Now copy the input data, splitting up channels */
t = ((int16_t*) ((uint8_t*) pa_memblock_acquire(input->memblock) + input->index)) + c;
k = (int16_t*) ((uint8_t*) p + l);
k = (int16_t*) ((uint8_t*) p);
for (u = 0; u < in_n_frames; u++) {
*k = *t;
t += r->o_ss.channels;
@ -1632,9 +1710,6 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
}
pa_memblock_release(input->memblock);
/* Calculate the resulting number of frames */
in = (unsigned) in_n_frames + l / (unsigned) sizeof(int16_t);
/* Allocate buffer for the result */
w = pa_memblock_new(r->mempool, *out_n_frames * sizeof(int16_t));
q = pa_memblock_acquire(w);
@ -1643,19 +1718,15 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
used_frames = (unsigned) av_resample(r->ffmpeg.state,
q, p,
&consumed_frames,
(int) in, (int) *out_n_frames,
(int) in_n_frames, (int) *out_n_frames,
c >= (unsigned) (r->o_ss.channels-1));
pa_memblock_release(b);
pa_memblock_unref(b);
/* Now store the remaining samples away */
pa_assert(consumed_frames <= (int) in);
if (consumed_frames < (int) in) {
r->ffmpeg.buf[c].memblock = b;
r->ffmpeg.buf[c].index = (size_t) consumed_frames * sizeof(int16_t);
r->ffmpeg.buf[c].length = (size_t) (in - (unsigned) consumed_frames) * sizeof(int16_t);
} else
pa_memblock_unref(b);
pa_assert(consumed_frames <= (int) in_n_frames);
pa_assert(previous_consumed_frames == -1 || consumed_frames == previous_consumed_frames);
previous_consumed_frames = consumed_frames;
/* And place the results in the output buffer */
s = (short*) ((uint8_t*) pa_memblock_acquire(output->memblock) + output->index) + c;
@ -1669,6 +1740,14 @@ static void ffmpeg_resample(pa_resampler *r, const pa_memchunk *input, unsigned
pa_memblock_unref(w);
}
if (previous_consumed_frames < (int) in_n_frames) {
void *leftover_data = (int16_t *) ((uint8_t *) pa_memblock_acquire(input->memblock) + output->index) + previous_consumed_frames * r->o_ss.channels;
size_t leftover_length = (in_n_frames - previous_consumed_frames) * r->o_ss.channels * sizeof(int16_t);
save_leftover(r, leftover_data, leftover_length);
pa_memblock_release(input->memblock);
}
*out_n_frames = used_frames;
}