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 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 --- src/pulsecore/resampler.c | 94 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 87 insertions(+), 7 deletions(-) diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c index 258d1fe..ef014f8 100644 --- a/src/pulsecore/resampler.c +++ b/src/pulsecore/resampler.c @@ -58,12 +58,16 @@ struct pa_resampler { pa_memchunk to_work_format_buf; pa_memchunk remap_buf; + pa_memchunk add_leftover_buf; /* For concatenating leftover with input. */ pa_memchunk resample_buf; pa_memchunk from_work_format_buf; + pa_memchunk leftover_buf; /* For storing the leftover data. */ unsigned to_work_format_buf_samples; unsigned remap_buf_samples; + unsigned add_leftover_buf_bytes; unsigned resample_buf_samples; unsigned from_work_format_buf_samples; + unsigned leftover_buf_bytes; pa_sample_format_t work_format; @@ -344,10 +348,14 @@ void pa_resampler_free(pa_resampler *r) { pa_memblock_unref(r->to_work_format_buf.memblock); if (r->remap_buf.memblock) pa_memblock_unref(r->remap_buf.memblock); + if (r->add_leftover_buf.memblock) + pa_memblock_unref(r->add_leftover_buf.memblock); if (r->resample_buf.memblock) pa_memblock_unref(r->resample_buf.memblock); if (r->from_work_format_buf.memblock) pa_memblock_unref(r->from_work_format_buf.memblock); + if (r->leftover_buf.memblock) + pa_memblock_unref(r->leftover_buf.memblock); pa_xfree(r); } @@ -379,17 +387,24 @@ 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) { pa_assert(r); - /* Let's round up here */ - - 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; + /* 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->leftover_buf.length / r->o_fz) * 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) { @@ -413,7 +428,7 @@ size_t pa_resampler_max_block_size(pa_resampler *r) { fs = pa_frame_size(&ss); - return (((block_size_max/fs - EXTRA_FRAMES)*r->i_ss.rate)/ss.rate)*r->i_fz; + return (((block_size_max / fs - EXTRA_FRAMES - r->leftover_buf.length / r->o_fz) * r->i_ss.rate) / ss.rate) * r->i_fz; } void pa_resampler_reset(pa_resampler *r) { @@ -421,6 +436,11 @@ void pa_resampler_reset(pa_resampler *r) { if (r->impl_reset) r->impl_reset(r); + + if (r->leftover_buf.memblock) { + pa_memblock_unref(r->leftover_buf.memblock); + r->leftover_buf.length = 0; + } } pa_resample_method_t pa_resampler_get_method(pa_resampler *r) { @@ -1143,6 +1163,48 @@ static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) { return &r->remap_buf; } +static pa_memchunk *add_leftover(pa_resampler *r, pa_memchunk *input) { + void *src; + void *dst; + + pa_assert(r); + pa_assert(input); + + /* Concatenate leftover and input and place the result in + * add_leftover_buf. */ + + if (r->leftover_buf.length <= 0) + return input; + + r->add_leftover_buf.length = r->leftover_buf.length + input->length; + + if (!r->add_leftover_buf.memblock || r->add_leftover_buf_bytes < r->add_leftover_buf.length) { + if (r->add_leftover_buf.memblock) + pa_memblock_unref(r->add_leftover_buf.memblock); + + r->add_leftover_buf_bytes = r->add_leftover_buf.length; + r->add_leftover_buf.memblock = pa_memblock_new(r->mempool, r->add_leftover_buf.length); + } + + src = (uint8_t *) pa_memblock_acquire(r->leftover_buf.memblock); + dst = pa_memblock_acquire(r->add_leftover_buf.memblock); + memcpy(dst, src, r->leftover_buf.length); + pa_memblock_release(r->leftover_buf.memblock); + + if (input->length > 0) { + src = (uint8_t *) pa_memblock_acquire(input->memblock) + input->index; + dst = (uint8_t *) dst + r->leftover_buf.length; + memcpy(dst, src, input->length); + pa_memblock_release(input->memblock); + } + + pa_memblock_release(r->add_leftover_buf.memblock); + + r->leftover_buf.length = 0; + + return &r->add_leftover_buf; +} + static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) { unsigned in_n_frames, in_n_samples; unsigned out_n_frames, out_n_samples; @@ -1229,6 +1291,7 @@ void pa_resampler_run(pa_resampler *r, const pa_memchunk *in, pa_memchunk *out) buf = (pa_memchunk*) in; buf = convert_to_work_format(r, buf); buf = remap_channels(r, buf); + buf = add_leftover(r, buf); buf = resample(r, buf); if (buf->length) { @@ -1266,7 +1329,24 @@ 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 *dst; + + r->leftover_buf.length = (in_n_frames - data.input_frames_used) * r->w_sz * r->o_ss.channels; + + if (!r->leftover_buf.memblock || r->leftover_buf_bytes < r->leftover_buf.length) { + if (r->leftover_buf.memblock) + pa_memblock_unref(r->leftover_buf.memblock); + + r->leftover_buf_bytes = r->leftover_buf.length; + r->leftover_buf.memblock = pa_memblock_new(r->mempool, r->leftover_buf.length); + } + + dst = pa_memblock_acquire(r->leftover_buf.memblock); + memcpy(dst, data.data_in + data.input_frames_used * r->o_ss.channels, r->leftover_buf.length); + pa_memblock_release(r->leftover_buf.memblock); + } pa_memblock_release(input->memblock); pa_memblock_release(output->memblock); -- 1.7.10
