[FFmpeg-devel] [PATCH 3/5] avcodec/bsf: Add list BSF API
sebechlebskyjan at gmail.com
sebechlebskyjan at gmail.com
Thu Jul 28 19:18:14 EEST 2016
From: Jan Sebechlebsky <sebechlebskyjan at gmail.com>
---
libavcodec/avcodec.h | 74 ++++++++++++++
libavcodec/bsf.c | 284 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 358 insertions(+)
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 36f7935..39106ee 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -5949,6 +5949,80 @@ void av_bsf_free(AVBSFContext **ctx);
*/
const AVClass *av_bsf_get_class(void);
+/**
+ * Structure for chain/list of bitstream filters.
+ * Empty list can be allocated by av_bsf_list_alloc().
+ */
+typedef struct AVBSFList AVBSFList;
+
+/**
+ * Allocate empty list of bitstream filters.
+ * The list must be later freed by av_bsf_list_free()
+ * or finalized by av_bsf_list_finalize().
+ *
+ * @return pointer to AVBSFList on success, NULL in case of failure
+ */
+AVBSFList *av_bsf_list_alloc(void);
+
+/**
+ * Free list of bitstream filters.
+ *
+ * @param lst pointer to pointer returned by av_bsf_list_alloc()
+ */
+void av_bsf_list_free(AVBSFList **lst);
+
+/**
+ * Append bitstream filter to the list of bitstream filters.
+ *
+ * @param lst list to append to
+ * @param bsf AVBSFContext to be appended
+ *
+ * @return >=0 on success, negative AVERROR in case of failure
+ */
+int av_bsf_list_append(AVBSFList *lst, AVBSFContext *bsf);
+
+/**
+ * Finalize list of bitstream filters.
+ *
+ * This function will transform AVBSFList to single AVBSFContext,
+ * so the whole chain of bitstream filters can be treated as single filter
+ * freshly allocated by av_bsf_alloc().
+ * The AVBSFList structure is destroyed after this call and must not
+ * be accessed.
+ *
+ * @param lst AVBSFList structure to be transformed
+ * @param bsf[out] pointer to be set to newly created AVBSFContext structure
+ * representing the chain of bitstream filters
+ *
+ * @return >=0 on success, negative AVERROR in case of failure
+ */
+int av_bsf_list_finalize(AVBSFList **lst, AVBSFContext **bsf);
+
+/**
+ * Parse string describing list of bitstream filters and create single
+ * AVBSFContext describing the whole chain of bitstream filters.
+ * Resulting AVBSFContext can be treated as any other AVBSFContext freshly
+ * allocated by av_bsf_alloc().
+ *
+ * @param str string describing chain of bitstream filters in format
+ * bsf1[=opt1=val1:opt2=val2][,bsf2]
+ * @param bsf[out] pointer to be set to newly created AVBSFContext structure
+ * representing the chain of bitstream filters
+ *
+ * @return >=0 on success, negative AVERROR in case of failure
+ */
+int av_bsf_list_parse_str(const char *str, AVBSFContext **bsf);
+
+/**
+ * Get null/pass-through bitstream filter.
+ *
+ * @param bsf[out] pointer to be set to new instance of pass-through
+ * bitstream filter
+ *
+ * @return
+ */
+int av_bsf_get_null_filter(AVBSFContext **bsf);
+
/* memory */
/**
diff --git a/libavcodec/bsf.c b/libavcodec/bsf.c
index 40fc925..3ae0a2b 100644
--- a/libavcodec/bsf.c
+++ b/libavcodec/bsf.c
@@ -22,6 +22,7 @@
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
#include "avcodec.h"
#include "bsf.h"
@@ -236,3 +237,286 @@ int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
return 0;
}
+
+typedef struct BSFListContext {
+ const AVClass *class;
+
+ AVBSFContext **bsf_lst;
+ int ctx_nr;
+
+ int idx; // index of currently processed BSF
+ int flushed_idx; // index of BSF being flushed
+
+} BSFListContext;
+
+
+static int bsf_list_init(AVBSFContext *bsf)
+{
+ BSFListContext *lst = bsf->priv_data;
+ int ret, i;
+ const AVCodecParameters *cod_par = bsf->par_in;
+ AVRational tb = bsf->time_base_in;
+
+ for (i = 0; i < lst->ctx_nr; ++i) {
+ ret = avcodec_parameters_copy(lst->bsf_lst[i]->par_in, cod_par);
+ if (ret < 0)
+ goto fail;
+
+ lst->bsf_lst[i]->time_base_in = tb;
+
+ ret = av_bsf_init(lst->bsf_lst[i]);
+ if (ret < 0)
+ goto fail;
+
+ cod_par = lst->bsf_lst[i]->par_out;
+ tb = lst->bsf_lst[i]->time_base_out;
+ }
+
+ bsf->time_base_out = tb;
+ ret = avcodec_parameters_copy(bsf->par_out, cod_par);
+
+fail:
+ return ret;
+}
+
+static int bsf_list_flush(AVBSFContext *bsf, AVPacket *out)
+{
+ BSFListContext *lst = bsf->priv_data;
+ int ret;
+
+ if (lst->flushed_idx == lst->ctx_nr)
+ return AVERROR_EOF;
+
+ while (1) {
+ if (lst->idx > lst->flushed_idx) {
+ ret = av_bsf_receive_packet(lst->bsf_lst[lst->idx-1], out);
+ if (ret == AVERROR(EAGAIN)) {
+ ret = 0;
+ lst->idx--;
+ continue;
+ } else if (ret == AVERROR_EOF) {
+ /* filter idx-1 is done, let's flush filter idx */
+ lst->flushed_idx = lst->idx;
+ continue;
+ } else if (ret < 0) {
+ /* filtering error */
+ break;
+ }
+ }
+
+ if (lst->idx < lst->ctx_nr) {
+ AVPacket *pkt = (lst->idx == lst->flushed_idx) ? NULL : out;
+ ret = av_bsf_send_packet(lst->bsf_lst[lst->idx], pkt);
+ if (ret < 0)
+ break;
+ lst->idx++;
+ } else {
+ /* The end of filter chain, break to return result */
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int bsf_list_filter(AVBSFContext *bsf, AVPacket *out)
+{
+ BSFListContext *lst = bsf->priv_data;
+ int ret;
+
+ if (!lst->ctx_nr)
+ return ff_bsf_get_packet_ref(bsf, out);
+
+ while (1) {
+ if (lst->idx) {
+ ret = av_bsf_receive_packet(lst->bsf_lst[lst->idx-1], out);
+ if (ret == AVERROR(EAGAIN)) {
+ ret = 0;
+ lst->idx--;
+ continue;
+ } else if (ret < 0) {
+ break;
+ }
+ } else {
+ ret = ff_bsf_get_packet_ref(bsf, out);
+ if (ret < 0)
+ break;
+ }
+
+ if (lst->idx < lst->ctx_nr) {
+ ret = av_bsf_send_packet(lst->bsf_lst[lst->idx], out);
+ if (ret < 0)
+ break;
+ lst->idx++;
+ } else {
+ break;
+ }
+ }
+
+ if (ret == AVERROR_EOF)
+ ret = bsf_list_flush(bsf, out);
+
+ if (ret < 0)
+ av_packet_unref(out);
+
+ return ret;
+}
+
+static void bsf_list_close(AVBSFContext *bsf)
+{
+ BSFListContext *lst = bsf->priv_data;
+ int i;
+
+ for (i = 0; i < lst->ctx_nr; ++i)
+ av_bsf_free(&lst->bsf_lst[i]);
+ av_freep(&lst->bsf_lst);
+}
+
+static const AVClass bsf_list_class = {
+ .class_name = "bsf_list",
+ .item_name = av_default_item_name,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+const AVBitStreamFilter ff_list_bsf = {
+ .name = "bsf_list",
+ .priv_data_size = sizeof(BSFListContext),
+ .priv_class = &bsf_list_class,
+ .init = bsf_list_init,
+ .filter = bsf_list_filter,
+ .close = bsf_list_close,
+};
+
+typedef struct AVBSFList {
+ AVBSFContext **bsf_lst;
+ int ctx_nr;
+} AVBSFList;
+
+AVBSFList *av_bsf_list_alloc(void)
+{
+ return av_mallocz(sizeof(AVBSFList));
+}
+
+void av_bsf_list_free(AVBSFList **lst)
+{
+ int i;
+ for (i = 0; i < (*lst)->ctx_nr; ++i)
+ av_bsf_free(&(*lst)->bsf_lst[i]);
+ av_free((*lst)->bsf_lst);
+ av_freep(lst);
+}
+
+int av_bsf_list_append(AVBSFList *lst, AVBSFContext *bsf)
+{
+ return av_dynarray_add_nofree(&lst->bsf_lst, &lst->ctx_nr, bsf);
+}
+
+int av_bsf_list_finalize(AVBSFList **lst, AVBSFContext **bsf)
+{
+ int ret = 0;
+ BSFListContext *ctx;
+
+ if ((*lst)->ctx_nr == 1) {
+ *bsf = (*lst)->bsf_lst[0];
+ (*lst)->bsf_lst = NULL;
+ (*lst)->ctx_nr = 0;
+ goto end;
+ }
+
+ ret = av_bsf_alloc(&ff_list_bsf, bsf);
+ if (ret < 0)
+ return ret;
+
+ ctx = (*bsf)->priv_data;
+
+ ctx->bsf_lst = (*lst)->bsf_lst;
+ ctx->ctx_nr = (*lst)->ctx_nr;
+
+end:
+ av_freep(lst);
+ return ret;
+}
+
+static int bsf_parse_str(const char *str, AVBSFContext **bsf)
+{
+ const AVBitStreamFilter *filter;
+ char *bsf_name, *bsf_options_str, *buf;
+ int ret = 0;
+
+ if (!(buf = av_strdup(str)))
+ return AVERROR(ENOMEM);
+
+ bsf_name = av_strtok(buf, "=", &bsf_options_str);
+ if (!bsf_name) {
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ filter = av_bsf_get_by_name(bsf_name);
+ if (!filter) {
+ ret = AVERROR_BSF_NOT_FOUND;
+ goto end;
+ }
+
+ ret = av_bsf_alloc(filter, bsf);
+ if (ret < 0)
+ goto end;
+
+ if (bsf_options_str) {
+ ret = av_set_options_string(*bsf, bsf_options_str, "=", ":");
+ if (ret < 0)
+ av_bsf_free(bsf);
+ }
+
+end:
+ av_free(buf);
+ return ret;
+}
+
+int av_bsf_list_parse_str(const char *str, AVBSFContext **bsf_lst)
+{
+ AVBSFList *lst;
+ char *bsf_str, *buf, *dup, *saveptr;
+ int ret;
+
+ if (!str)
+ return av_bsf_get_null_filter(bsf_lst);
+
+ lst = av_bsf_list_alloc();
+ if (!lst)
+ return AVERROR(ENOMEM);
+
+ if (!(dup = buf = av_strdup(str)))
+ return AVERROR(ENOMEM);
+
+ while (1) {
+ AVBSFContext *bsf;
+ bsf_str = av_strtok(buf, ",", &saveptr);
+ if (!bsf_str)
+ break;
+
+ ret = bsf_parse_str(bsf_str, &bsf);
+ if (ret < 0)
+ goto end;
+
+ ret = av_bsf_list_append(lst, bsf);
+ if (ret < 0) {
+ av_bsf_free(&bsf);
+ goto end;
+ }
+
+ buf = NULL;
+ }
+
+ ret = av_bsf_list_finalize(&lst, bsf_lst);
+end:
+ if (ret < 0)
+ av_bsf_list_free(&lst);
+ av_free(dup);
+ return ret;
+}
+
+int av_bsf_get_null_filter(AVBSFContext **bsf)
+{
+ return av_bsf_alloc(&ff_list_bsf, bsf);
+}
--
1.9.1
More information about the ffmpeg-devel
mailing list