diff options
| -rw-r--r-- | doc/APIchanges | 9 | ||||
| -rw-r--r-- | libavutil/fifo.c | 226 | ||||
| -rw-r--r-- | libavutil/fifo.h | 179 | ||||
| -rw-r--r-- | libavutil/version.h | 2 |
4 files changed, 415 insertions, 1 deletions
diff --git a/doc/APIchanges b/doc/APIchanges index 315a04c952..ca9c476346 100644 --- a/doc/APIchanges +++ b/doc/APIchanges @@ -14,6 +14,15 @@ libavutil: 2021-04-27 API changes, most recent first: +2022-02-07 - xxxxxxxxxx - lavu 57.20.100 - fifo.h + Add a new FIFO API, which allows setting a FIFO element size. + This API operates on these elements rather than on bytes. + Add av_fifo_alloc2(), av_fifo_elem_size(), av_fifo_can_read(), + av_fifo_can_write(), av_fifo_grow2(), av_fifo_drain2(), av_fifo_write(), + av_fifo_write_from_cb(), av_fifo_read(), av_fifo_read_to_cb(), + av_fifo_peek(), av_fifo_peek_to_cb(), av_fifo_drain2(), av_fifo_reset2(), + av_fifo_freep2(). + 2022-01-26 - af94ab7c7c0 - lavu 57.19.100 - tx.h Add AV_TX_FLOAT_RDFT, AV_TX_DOUBLE_RDFT and AV_TX_INT32_RDFT. diff --git a/libavutil/fifo.c b/libavutil/fifo.c index 55621f0dca..0001ccbd43 100644 --- a/libavutil/fifo.c +++ b/libavutil/fifo.c @@ -26,6 +26,232 @@ #include "common.h" #include "fifo.h" +struct AVFifo { + uint8_t *buffer; + + size_t elem_size, nb_elems; + size_t offset_r, offset_w; + // distinguishes the ambiguous situation offset_r == offset_w + int is_empty; +}; + +AVFifo *av_fifo_alloc2(size_t nb_elems, size_t elem_size, + unsigned int flags) +{ + AVFifo *f; + void *buffer = NULL; + + if (!elem_size) + return NULL; + + if (nb_elems) { + buffer = av_realloc_array(NULL, nb_elems, elem_size); + if (!buffer) + return NULL; + } + f = av_mallocz(sizeof(*f)); + if (!f) { + av_free(buffer); + return NULL; + } + f->buffer = buffer; + f->nb_elems = nb_elems; + f->elem_size = elem_size; + f->is_empty = 1; + + return f; +} + +size_t av_fifo_elem_size(const AVFifo *f) +{ + return f->elem_size; +} + +size_t av_fifo_can_read(const AVFifo *f) +{ + if (f->offset_w <= f->offset_r && !f->is_empty) + return f->nb_elems - f->offset_r + f->offset_w; + return f->offset_w - f->offset_r; +} + +size_t av_fifo_can_write(const AVFifo *f) +{ + return f->nb_elems - av_fifo_can_read(f); +} + +int av_fifo_grow2(AVFifo *f, size_t inc) +{ + uint8_t *tmp; + + if (inc > SIZE_MAX - f->nb_elems) + return AVERROR(EINVAL); + + tmp = av_realloc_array(f->buffer, f->nb_elems + inc, f->elem_size); + if (!tmp) + return AVERROR(ENOMEM); + f->buffer = tmp; + + // move the data from the beginning of the ring buffer + // to the newly allocated space + if (f->offset_w <= f->offset_r && !f->is_empty) { + const size_t copy = FFMIN(inc, f->offset_w); + memcpy(tmp + f->nb_elems * f->elem_size, tmp, copy * f->elem_size); + if (copy < f->offset_w) { + memmove(tmp, tmp + copy * f->elem_size, + (f->offset_w - copy) * f->elem_size); + f->offset_w -= copy; + } else + f->offset_w = f->nb_elems + copy; + } + + f->nb_elems += inc; + + return 0; +} + +static int fifo_write_common(AVFifo *f, const uint8_t *buf, size_t *nb_elems, + AVFifoCB read_cb, void *opaque) +{ + size_t to_write = *nb_elems; + size_t offset_w = f->offset_w; + int ret = 0; + + if (to_write > av_fifo_can_write(f)) + return AVERROR(ENOSPC); + + while (to_write > 0) { + size_t len = FFMIN(f->nb_elems - offset_w, to_write); + uint8_t *wptr = f->buffer + offset_w * f->elem_size; + + if (read_cb) { + ret = read_cb(opaque, wptr, &len); + if (ret < 0 || len == 0) + break; + } else { + memcpy(wptr, buf, len * f->elem_size); + buf += len * f->elem_size; + } + offset_w += len; + if (offset_w >= f->nb_elems) + offset_w = 0; + to_write -= len; + } + f->offset_w = offset_w; + + if (*nb_elems != to_write) + f->is_empty = 0; + *nb_elems -= to_write; + + return ret; +} + +int av_fifo_write(AVFifo *f, const void *buf, size_t nb_elems) +{ + return fifo_write_common(f, buf, &nb_elems, NULL, NULL); +} + +int av_fifo_write_from_cb(AVFifo *f, AVFifoCB read_cb, + void *opaque, size_t *nb_elems) +{ + return fifo_write_common(f, NULL, nb_elems, read_cb, opaque); +} + +static int fifo_peek_common(const AVFifo *f, uint8_t *buf, size_t *nb_elems, + size_t offset, AVFifoCB write_cb, void *opaque) +{ + size_t to_read = *nb_elems; + size_t offset_r = f->offset_r; + size_t can_read = av_fifo_can_read(f); + int ret = 0; + + if (offset > can_read || to_read > can_read - offset) { + *nb_elems = 0; + return AVERROR(EINVAL); + } + + if (offset_r >= f->nb_elems - offset) + offset_r -= f->nb_elems - offset; + else + offset_r += offset; + + while (to_read > 0) { + size_t len = FFMIN(f->nb_elems - offset_r, to_read); + uint8_t *rptr = f->buffer + offset_r * f->elem_size; + + if (write_cb) { + ret = write_cb(opaque, rptr, &len); + if (ret < 0 || len == 0) + break; + } else { + memcpy(buf, rptr, len * f->elem_size); + buf += len * f->elem_size; + } + offset_r += len; + if (offset_r >= f->nb_elems) + offset_r = 0; + to_read -= len; + } + + *nb_elems -= to_read; + + return ret; +} + +int av_fifo_read(AVFifo *f, void *buf, size_t nb_elems) +{ + int ret = fifo_peek_common(f, buf, &nb_elems, 0, NULL, NULL); + av_fifo_drain2(f, nb_elems); + return ret; +} + +int av_fifo_read_to_cb(AVFifo *f, AVFifoCB write_cb, + void *opaque, size_t *nb_elems) +{ + int ret = fifo_peek_common(f, NULL, nb_elems, 0, write_cb, opaque); + av_fifo_drain2(f, *nb_elems); + return ret; +} + +int av_fifo_peek(AVFifo *f, void *buf, size_t nb_elems, size_t offset) +{ + return fifo_peek_common(f, buf, &nb_elems, offset, NULL, NULL); +} + +int av_fifo_peek_to_cb(AVFifo *f, AVFifoCB write_cb, void *opaque, + size_t *nb_elems, size_t offset) +{ + return fifo_peek_common(f, NULL, nb_elems, offset, write_cb, opaque); +} + +void av_fifo_drain2(AVFifo *f, size_t size) +{ + const size_t cur_size = av_fifo_can_read(f); + + av_assert0(cur_size >= size); + if (cur_size == size) + f->is_empty = 1; + + if (f->offset_r >= f->nb_elems - size) + f->offset_r -= f->nb_elems - size; + else + f->offset_r += size; +} + +void av_fifo_reset2(AVFifo *f) +{ + f->offset_r = f->offset_w = 0; + f->is_empty = 1; +} + +void av_fifo_freep2(AVFifo **f) +{ + if (*f) { + av_freep(&(*f)->buffer); + av_freep(f); + } +} + + #define OLD_FIFO_SIZE_MAX (size_t)FFMIN3(INT_MAX, UINT32_MAX, SIZE_MAX) AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size) diff --git a/libavutil/fifo.h b/libavutil/fifo.h index f4fd291e59..f455022e3c 100644 --- a/libavutil/fifo.h +++ b/libavutil/fifo.h @@ -28,6 +28,185 @@ #include "avutil.h" #include "attributes.h" +typedef struct AVFifo AVFifo; + +/** + * Callback for writing or reading from a FIFO, passed to (and invoked from) the + * av_fifo_*_cb() functions. It may be invoked multiple times from a single + * av_fifo_*_cb() call and may process less data than the maximum size indicated + * by nb_elems. + * + * @param opaque the opaque pointer provided to the av_fifo_*_cb() function + * @param buf the buffer for reading or writing the data, depending on which + * av_fifo_*_cb function is called + * @param nb_elems On entry contains the maximum number of elements that can be + * read from / written into buf. On success, the callback should + * update it to contain the number of elements actually written. + * + * @return 0 on success, a negative error code on failure (will be returned from + * the invoking av_fifo_*_cb() function) + */ +typedef int AVFifoCB(void *opaque, void *buf, size_t *nb_elems); + +/** + * Allocate and initialize an AVFifo with a given element size. + * + * @param elems initial number of elements that can be stored in the FIFO + * @param elem_size Size in bytes of a single element. Further operations on + * the returned FIFO will implicitly use this element size. + * @param flags currently unused, must be 0 + * + * @return newly-allocated AVFifo on success, a negative error code on failure + */ +AVFifo *av_fifo_alloc2(size_t elems, size_t elem_size, + unsigned int flags); + +/** + * @return Element size for FIFO operations. This element size is set at + * FIFO allocation and remains constant during its lifetime + */ +size_t av_fifo_elem_size(const AVFifo *f); + +/** + * @return number of elements available for reading from the given FIFO. + */ +size_t av_fifo_can_read(const AVFifo *f); + +/** + * @return number of elements that can be written into the given FIFO. + */ +size_t av_fifo_can_write(const AVFifo *f); + +/** + * Enlarge an AVFifo. + * + * On success, the FIFO will be large enough to hold exactly + * inc + av_fifo_can_read() + av_fifo_can_write() + * elements. In case of failure, the old FIFO is kept unchanged. + * + * @param f AVFifo to resize + * @param inc number of elements to allocate for, in addition to the current + * allocated size + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_grow2(AVFifo *f, size_t inc); + +/** + * Write data into a FIFO. + * + * In case nb_elems > av_fifo_can_write(f), nothing is written and an error + * is returned. + * + * @param f the FIFO buffer + * @param buf Data to be written. nb_elems * av_fifo_elem_size(f) bytes will be + * read from buf on success. + * @param nb_elems number of elements to write into FIFO + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_write(AVFifo *f, const void *buf, size_t nb_elems); + +/** + * Write data from a user-provided callback into a FIFO. + * + * @param f the FIFO buffer + * @param read_cb Callback supplying the data to the FIFO. May be called + * multiple times. + * @param opaque opaque user data to be provided to read_cb + * @param nb_elems Should point to the maximum number of elements that can be + * written. Will be updated to contain the number of elements + * actually written. + * + * @return non-negative number on success, a negative error code on failure + */ +int av_fifo_write_from_cb(AVFifo *f, AVFifoCB read_cb, + void *opaque, size_t *nb_elems); + +/** + * Read data from a FIFO. + * + * In case nb_elems > av_fifo_can_read(f), nothing is read and an error + * is returned. + * + * @param f the FIFO buffer + * @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes + * will be written into buf on success. + * @param nb_elems number of elements to read from FIFO + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_read(AVFifo *f, void *buf, size_t nb_elems); + +/** + * Feed data from a FIFO into a user-provided callback. + * + * @param f the FIFO buffer + * @param write_cb Callback the data will be supplied to. May be called + * multiple times. + * @param opaque opaque user data to be provided to write_cb + * @param nb_elems Should point to the maximum number of elements that can be + * read. Will be updated to contain the total number of elements + * actually sent to the callback. + * + * @return non-negative number on success, a negative error code on failure + */ +int av_fifo_read_to_cb(AVFifo *f, AVFifoCB write_cb, + void *opaque, size_t *nb_elems); + +/** + * Read data from a FIFO without modifying FIFO state. + * + * Returns an error if an attempt is made to peek to nonexistent elements + * (i.e. if offset + nb_elems is larger than av_fifo_can_read(f)). + * + * @param f the FIFO buffer + * @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes + * will be written into buf. + * @param nb_elems number of elements to read from FIFO + * @param offset number of initial elements to skip. + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_peek(AVFifo *f, void *buf, size_t nb_elems, size_t offset); + +/** + * Feed data from a FIFO into a user-provided callback. + * + * @param f the FIFO buffer + * @param write_cb Callback the data will be supplied to. May be called + * multiple times. + * @param opaque opaque user data to be provided to write_cb + * @param nb_elems Should point to the maximum number of elements that can be + * read. Will be updated to contain the total number of elements + * actually sent to the callback. + * @param offset number of initial elements to skip; offset + *nb_elems must not + * be larger than av_fifo_can_read(f). + * + * @return a non-negative number on success, a negative error code on failure + */ +int av_fifo_peek_to_cb(AVFifo *f, AVFifoCB write_cb, void *opaque, + size_t *nb_elems, size_t offset); + +/** + * Discard the specified amount of data from an AVFifo. + * @param size number of elements to discard, MUST NOT be larger than + * av_fifo_can_read(f) + */ +void av_fifo_drain2(AVFifo *f, size_t size); + +/* + * Empty the AVFifo. + * @param f AVFifo to reset + */ +void av_fifo_reset2(AVFifo *f); + +/** + * Free an AVFifo and reset pointer to NULL. + * @param f Pointer to an AVFifo to free. *f == NULL is allowed. + */ +void av_fifo_freep2(AVFifo **f); + + typedef struct AVFifoBuffer { uint8_t *buffer; uint8_t *rptr, *wptr, *end; diff --git a/libavutil/version.h b/libavutil/version.h index 331b8f6ea9..f961077849 100644 --- a/libavutil/version.h +++ b/libavutil/version.h @@ -79,7 +79,7 @@ */ #define LIBAVUTIL_VERSION_MAJOR 57 -#define LIBAVUTIL_VERSION_MINOR 19 +#define LIBAVUTIL_VERSION_MINOR 20 #define LIBAVUTIL_VERSION_MICRO 100 #define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \ |