Anton Khirnov: > Use separate functions for writing from a buffer and a callback, since > the overwhelming majority of callers use a buffer and should not be > forced to pass extra NULL parameters or use a longer name. > > Consistently use size_t for sizes. > --- > doc/APIchanges | 2 +- > libavutil/fifo.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++ > libavutil/fifo.h | 46 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 105 insertions(+), 1 deletion(-) > > diff --git a/doc/APIchanges b/doc/APIchanges > index f2769d4165..0b179c30e5 100644 > --- a/doc/APIchanges > +++ b/doc/APIchanges > @@ -19,7 +19,7 @@ API changes, most recent first: > Operations on FIFOs created with this function on these elements > rather than bytes. > Add av_fifo_elem_size(), av_fifo_can_read(), av_fifo_can_write(), > - av_fifo_grow2(), av_fifo_drain2(). > + av_fifo_grow2(), av_fifo_drain2(), av_fifo_write(), > av_fifo_write_from_cb(). > > 2022-01-xx - xxxxxxxxxx - lavu fifo.h > Access to all AVFifoBuffer members is deprecated. The struct will > diff --git a/libavutil/fifo.c b/libavutil/fifo.c > index e9f439e219..1d94fff457 100644 > --- a/libavutil/fifo.c > +++ b/libavutil/fifo.c > @@ -207,6 +207,64 @@ void av_fifo_drain2(AVFifoBuffer *f, size_t size) > #endif > } > > +static int fifo_write_common(AVFifoBuffer *f, const uint8_t *buf, size_t > *nb_elems, > + AVFifoCB read_cb, void *opaque)
Should be write_cb. > +{ > + FifoBuffer *fb = (FifoBuffer*)f; > + size_t to_write = *nb_elems; How about calling this "left"? > + size_t offset_w = fb->offset_w; > + int ret = 0; > +#if FF_API_FIFO_PUBLIC > + uint32_t wndx= f->wndx; > +#endif > + > + if (to_write > av_fifo_can_write(f)) > + return AVERROR(ENOSPC); > + > + do { > + size_t len = FFMIN(fb->nb_elems - offset_w, to_write); > + uint8_t *wptr = f->buffer + offset_w * fb->elem_size; > + > + if (read_cb) { > + ret = read_cb(opaque, wptr, &len); > + if (ret < 0 || len == 0) > + break; > + } else { > + memcpy(wptr, buf, len * fb->elem_size); > + buf += len * fb->elem_size; > + } > + offset_w += len; > + if (offset_w >= fb->nb_elems) > + offset_w = 0; > +#if FF_API_FIFO_PUBLIC > + wndx += len; > +#endif > + to_write -= len; > + } while (to_write > 0); > +#if FF_API_FIFO_PUBLIC > + f->wndx= wndx; > + f->wptr= f->buffer + offset_w * fb->elem_size; > +#endif > + fb->offset_w = offset_w; > + > + if (*nb_elems - to_write > 0) to_write < *nb_elems > + fb->is_empty = 0; > + *nb_elems -= to_write; > + > + return ret; > +} > + > +int av_fifo_write(AVFifoBuffer *f, const void *buf, size_t nb_elems) > +{ > + return fifo_write_common(f, buf, &nb_elems, NULL, NULL); > +} > + > +int av_fifo_write_from_cb(AVFifoBuffer *f, AVFifoCB read_cb, > + void *opaque, size_t *nb_elems) > +{ > + return fifo_write_common(f, NULL, nb_elems, read_cb, opaque); > +} > + > int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) > { > FifoBuffer *fb = (FifoBuffer*)f; > diff --git a/libavutil/fifo.h b/libavutil/fifo.h > index d593304edb..ac1245ff39 100644 > --- a/libavutil/fifo.h > +++ b/libavutil/fifo.h > @@ -44,6 +44,24 @@ typedef struct AVFifoBuffer > #endif > AVFifoBuffer; > > +/** > + * 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. The last sentence is write-only, although this callback is also used for reading. > + * > + * @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); > + > /** > * Initialize an AVFifoBuffer. > * @param size of FIFO > @@ -143,6 +161,34 @@ size_t av_fifo_can_write(const AVFifoBuffer *f); > */ > int av_fifo_grow2(AVFifoBuffer *f, size_t inc); > > +/** > + * Write data into a FIFO. > + * > + * @param f the FIFO buffer > + * @param buf Data to be written. nb_elems * av_fifo_elem_size(f) bytes will > be > + * read from buf. > + * @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(AVFifoBuffer *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(AVFifoBuffer *f, AVFifoCB read_cb, s/read_cb/write_cb/ (also above) > + void *opaque, size_t *nb_elems); > + > /** > * Discard the specified amount of data from an AVFifoBuffer. > * @param size number of elements to discard, MUST NOT be larger than > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".