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Diffstat (limited to 'media/ffvpx/libavutil/fifo.c')
| -rw-r--r-- | media/ffvpx/libavutil/fifo.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/fifo.c b/media/ffvpx/libavutil/fifo.c new file mode 100644 index 000000000..1060aedf1 --- /dev/null +++ b/media/ffvpx/libavutil/fifo.c @@ -0,0 +1,240 @@ +/* + * a very simple circular buffer FIFO implementation + * Copyright (c) 2000, 2001, 2002 Fabrice Bellard + * Copyright (c) 2006 Roman Shaposhnik + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avassert.h" +#include "common.h" +#include "fifo.h" + +static AVFifoBuffer *fifo_alloc_common(void *buffer, size_t size) +{ + AVFifoBuffer *f; + if (!buffer) + return NULL; + f = av_mallocz(sizeof(AVFifoBuffer)); + if (!f) { + av_free(buffer); + return NULL; + } + f->buffer = buffer; + f->end = f->buffer + size; + av_fifo_reset(f); + return f; +} + +AVFifoBuffer *av_fifo_alloc(unsigned int size) +{ + void *buffer = av_malloc(size); + return fifo_alloc_common(buffer, size); +} + +AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size) +{ + void *buffer = av_malloc_array(nmemb, size); + return fifo_alloc_common(buffer, nmemb * size); +} + +void av_fifo_free(AVFifoBuffer *f) +{ + if (f) { + av_freep(&f->buffer); + av_free(f); + } +} + +void av_fifo_freep(AVFifoBuffer **f) +{ + if (f) { + av_fifo_free(*f); + *f = NULL; + } +} + +void av_fifo_reset(AVFifoBuffer *f) +{ + f->wptr = f->rptr = f->buffer; + f->wndx = f->rndx = 0; +} + +int av_fifo_size(const AVFifoBuffer *f) +{ + return (uint32_t)(f->wndx - f->rndx); +} + +int av_fifo_space(const AVFifoBuffer *f) +{ + return f->end - f->buffer - av_fifo_size(f); +} + +int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) +{ + unsigned int old_size = f->end - f->buffer; + + if (old_size < new_size) { + int len = av_fifo_size(f); + AVFifoBuffer *f2 = av_fifo_alloc(new_size); + + if (!f2) + return AVERROR(ENOMEM); + av_fifo_generic_read(f, f2->buffer, len, NULL); + f2->wptr += len; + f2->wndx += len; + av_free(f->buffer); + *f = *f2; + av_free(f2); + } + return 0; +} + +int av_fifo_grow(AVFifoBuffer *f, unsigned int size) +{ + unsigned int old_size = f->end - f->buffer; + if(size + (unsigned)av_fifo_size(f) < size) + return AVERROR(EINVAL); + + size += av_fifo_size(f); + + if (old_size < size) + return av_fifo_realloc2(f, FFMAX(size, 2*old_size)); + return 0; +} + +/* src must NOT be const as it can be a context for func that may need + * updating (like a pointer or byte counter) */ +int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, + int (*func)(void *, void *, int)) +{ + int total = size; + uint32_t wndx= f->wndx; + uint8_t *wptr= f->wptr; + + do { + int len = FFMIN(f->end - wptr, size); + if (func) { + len = func(src, wptr, len); + if (len <= 0) + break; + } else { + memcpy(wptr, src, len); + src = (uint8_t *)src + len; + } +// Write memory barrier needed for SMP here in theory + wptr += len; + if (wptr >= f->end) + wptr = f->buffer; + wndx += len; + size -= len; + } while (size > 0); + f->wndx= wndx; + f->wptr= wptr; + return total - size; +} + +int av_fifo_generic_peek_at(AVFifoBuffer *f, void *dest, int offset, int buf_size, void (*func)(void*, void*, int)) +{ + uint8_t *rptr = f->rptr; + + av_assert2(offset >= 0); + + /* + * *ndx are indexes modulo 2^32, they are intended to overflow, + * to handle *ndx greater than 4gb. + */ + av_assert2(buf_size + (unsigned)offset <= f->wndx - f->rndx); + + if (offset >= f->end - rptr) + rptr += offset - (f->end - f->buffer); + else + rptr += offset; + + while (buf_size > 0) { + int len; + + if (rptr >= f->end) + rptr -= f->end - f->buffer; + + len = FFMIN(f->end - rptr, buf_size); + if (func) + func(dest, rptr, len); + else { + memcpy(dest, rptr, len); + dest = (uint8_t *)dest + len; + } + + buf_size -= len; + rptr += len; + } + + return 0; +} + +int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size, + void (*func)(void *, void *, int)) +{ +// Read memory barrier needed for SMP here in theory + uint8_t *rptr = f->rptr; + + do { + int len = FFMIN(f->end - rptr, buf_size); + if (func) + func(dest, rptr, len); + else { + memcpy(dest, rptr, len); + dest = (uint8_t *)dest + len; + } +// memory barrier needed for SMP here in theory + rptr += len; + if (rptr >= f->end) + rptr -= f->end - f->buffer; + buf_size -= len; + } while (buf_size > 0); + + return 0; +} + +int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, + void (*func)(void *, void *, int)) +{ +// Read memory barrier needed for SMP here in theory + do { + int len = FFMIN(f->end - f->rptr, buf_size); + if (func) + func(dest, f->rptr, len); + else { + memcpy(dest, f->rptr, len); + dest = (uint8_t *)dest + len; + } +// memory barrier needed for SMP here in theory + av_fifo_drain(f, len); + buf_size -= len; + } while (buf_size > 0); + return 0; +} + +/** Discard data from the FIFO. */ +void av_fifo_drain(AVFifoBuffer *f, int size) +{ + av_assert2(av_fifo_size(f) >= size); + f->rptr += size; + if (f->rptr >= f->end) + f->rptr -= f->end - f->buffer; + f->rndx += size; +} |