[FFmpeg-devel] [PATCH v2 07/13] cbs: Implement common parts of cbs-based bitstream filters separately
Mark Thompson
sw at jkqxz.net
Tue Jan 19 00:44:49 EET 2021
This allows removal of a lot of duplicated code between BSFs.
---
libavcodec/Makefile | 2 +-
libavcodec/cbs_bsf.c | 159 +++++++++++++++++++++++++++++++++++++++++++
libavcodec/cbs_bsf.h | 131 +++++++++++++++++++++++++++++++++++
3 files changed, 291 insertions(+), 1 deletion(-)
create mode 100644 libavcodec/cbs_bsf.c
create mode 100644 libavcodec/cbs_bsf.h
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 1fcb94fa48..6c1e7a1c7a 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -69,7 +69,7 @@ OBJS-$(CONFIG_AUDIODSP) += audiodsp.o
OBJS-$(CONFIG_BLOCKDSP) += blockdsp.o
OBJS-$(CONFIG_BSWAPDSP) += bswapdsp.o
OBJS-$(CONFIG_CABAC) += cabac.o
-OBJS-$(CONFIG_CBS) += cbs.o
+OBJS-$(CONFIG_CBS) += cbs.o cbs_bsf.o
OBJS-$(CONFIG_CBS_AV1) += cbs_av1.o
OBJS-$(CONFIG_CBS_H264) += cbs_h2645.o cbs_sei.o h2645_parse.o
OBJS-$(CONFIG_CBS_H265) += cbs_h2645.o cbs_sei.o h2645_parse.o
diff --git a/libavcodec/cbs_bsf.c b/libavcodec/cbs_bsf.c
new file mode 100644
index 0000000000..9b521cf111
--- /dev/null
+++ b/libavcodec/cbs_bsf.c
@@ -0,0 +1,159 @@
+/*
+ * 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 "bsf_internal.h"
+#include "cbs_bsf.h"
+
+static int cbs_bsf_update_side_data(AVBSFContext *bsf, AVPacket *pkt)
+{
+ CBSBSFContext *ctx = bsf->priv_data;
+ CodedBitstreamFragment *frag = &ctx->fragment;
+ uint8_t *side_data;
+ int side_data_size;
+ int err;
+
+ side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
+ &side_data_size);
+ if (!side_data_size)
+ return 0;
+
+ err = ff_cbs_read(ctx->input, frag, side_data, side_data_size);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR,
+ "Failed to read extradata from packet side data.\n");
+ return err;
+ }
+
+ err = ctx->type->update_fragment(bsf, NULL, frag);
+ if (err < 0)
+ return err;
+
+ err = ff_cbs_write_fragment_data(ctx->output, frag);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR,
+ "Failed to write extradata into packet side data.\n");
+ return err;
+ }
+
+ side_data = av_packet_new_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
+ frag->data_size);
+ if (!side_data)
+ return AVERROR(ENOMEM);
+ memcpy(side_data, frag->data, frag->data_size);
+
+ ff_cbs_fragment_reset(frag);
+ return 0;
+}
+
+int ff_cbs_bsf_generic_filter(AVBSFContext *bsf, AVPacket *pkt)
+{
+ CBSBSFContext *ctx = bsf->priv_data;
+ CodedBitstreamFragment *frag = &ctx->fragment;
+ int err;
+
+ err = ff_bsf_get_packet_ref(bsf, pkt);
+ if (err < 0)
+ return err;
+
+ err = cbs_bsf_update_side_data(bsf, pkt);
+ if (err < 0)
+ goto fail;
+
+ err = ff_cbs_read_packet(ctx->input, frag, pkt);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to read %s from packet.\n",
+ ctx->type->fragment_name);
+ goto fail;
+ }
+
+ if (frag->nb_units == 0) {
+ av_log(bsf, AV_LOG_ERROR, "No %s found in packet.\n",
+ ctx->type->unit_name);
+ err = AVERROR_INVALIDDATA;
+ goto fail;
+ }
+
+ err = ctx->type->update_fragment(bsf, pkt, frag);
+ if (err < 0)
+ goto fail;
+
+ err = ff_cbs_write_packet(ctx->output, pkt, frag);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to write %s into packet.\n",
+ ctx->type->fragment_name);
+ goto fail;
+ }
+
+ err = 0;
+fail:
+ ff_cbs_fragment_reset(frag);
+
+ if (err < 0)
+ av_packet_unref(pkt);
+
+ return err;
+}
+
+int ff_cbs_bsf_generic_init(AVBSFContext *bsf, const CBSBSFType *type)
+{
+ CBSBSFContext *ctx = bsf->priv_data;
+ CodedBitstreamFragment *frag = &ctx->fragment;
+ int err;
+
+ ctx->type = type;
+
+ err = ff_cbs_init(&ctx->input, type->codec_id, bsf);
+ if (err < 0)
+ return err;
+
+ err = ff_cbs_init(&ctx->output, type->codec_id, bsf);
+ if (err < 0)
+ return err;
+
+ if (bsf->par_in->extradata) {
+ err = ff_cbs_read_extradata(ctx->input, frag, bsf->par_in);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to read extradata.\n");
+ goto fail;
+ }
+
+ err = type->update_fragment(bsf, NULL, frag);
+ if (err < 0)
+ goto fail;
+
+ err = ff_cbs_write_extradata(ctx->output, bsf->par_out, frag);
+ if (err < 0) {
+ av_log(bsf, AV_LOG_ERROR, "Failed to write extradata.\n");
+ goto fail;
+ }
+ }
+
+ err = 0;
+fail:
+ ff_cbs_fragment_reset(frag);
+ return err;
+}
+
+void ff_cbs_bsf_generic_close(AVBSFContext *bsf)
+{
+ CBSBSFContext *ctx = bsf->priv_data;
+
+ ff_cbs_fragment_free(&ctx->fragment);
+ ff_cbs_close(&ctx->input);
+ ff_cbs_close(&ctx->output);
+}
diff --git a/libavcodec/cbs_bsf.h b/libavcodec/cbs_bsf.h
new file mode 100644
index 0000000000..5b1a88d4cb
--- /dev/null
+++ b/libavcodec/cbs_bsf.h
@@ -0,0 +1,131 @@
+/*
+ * 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
+ */
+
+#ifndef AVCODEC_CBS_BSF_H
+#define AVCODEC_CBS_BSF_H
+
+#include "cbs.h"
+
+
+typedef struct CBSBSFType {
+ enum AVCodecID codec_id;
+
+ // Name of a frame fragment in this codec (e.g. "access unit",
+ // "temporal unit").
+ const char *fragment_name;
+
+ // Name of a unit for this BSF, for use in error messages (e.g.
+ // "NAL unit", "OBU").
+ const char *unit_name;
+
+ // Update the content of a fragment with whatever metadata changes
+ // are desired. The associated AVPacket is provided so that any side
+ // data associated with the fragment can be inspected or edited. If
+ // pkt is NULL, then an extradata header fragment is being updated.
+ int (*update_fragment)(AVBSFContext *bsf, AVPacket *pkt,
+ CodedBitstreamFragment *frag);
+} CBSBSFType;
+
+// Common structure for all generic CBS BSF users. An instance of this
+// structure must be the first member of the BSF private context (to be
+// pointed to by AVBSFContext.priv_data).
+typedef struct CBSBSFContext {
+ const AVClass *class;
+ const CBSBSFType *type;
+
+ CodedBitstreamContext *input;
+ CodedBitstreamContext *output;
+ CodedBitstreamFragment fragment;
+} CBSBSFContext;
+
+/**
+ * Initialise generic CBS BSF setup.
+ *
+ * Creates the input and output CBS instances, and applies the filter to
+ * the extradata on the input codecpar if any is present.
+ *
+ * Since it calls the update_fragment() function immediately to deal with
+ * extradata, this should be called after any codec-specific setup is done
+ * (probably at the end of the AVBitStreamFilter.init function).
+ */
+int ff_cbs_bsf_generic_init(AVBSFContext *bsf, const CBSBSFType *type);
+
+/**
+ * Close a generic CBS BSF instance.
+ *
+ * If no other deinitialisation is required then this function can be used
+ * directly as AVBitStreamFilter.close.
+ */
+void ff_cbs_bsf_generic_close(AVBSFContext *bsf);
+
+/**
+ * Filter operation for CBS BSF.
+ *
+ * Reads the input packet into a CBS fragment, calls update_fragment() on
+ * it, then writes the result to an output packet. If the input packet
+ * has AV_PKT_DATA_NEW_EXTRADATA side-data associated with it then it does
+ * the same thing to that new extradata to form the output side-data first.
+ *
+ * If the BSF does not do anything else then this function can be used
+ * directly as AVBitStreamFilter.filter.
+ */
+int ff_cbs_bsf_generic_filter(AVBSFContext *bsf, AVPacket *pkt);
+
+
+// Options for element manipulation.
+enum {
+ // Pass this element through unchanged.
+ BSF_ELEMENT_PASS,
+ // Insert this element, replacing any existing instances of it.
+ // Associated values may be provided explicitly (as addtional options)
+ // or implicitly (either as side data or deduced from other parts of
+ // the stream).
+ BSF_ELEMENT_INSERT,
+ // Remove this element if it appears in the stream.
+ BSF_ELEMENT_REMOVE,
+ // Extract this element to side data, so that further manipulation
+ // can happen elsewhere.
+ BSF_ELEMENT_EXTRACT,
+};
+
+#define BSF_ELEMENT_OPTIONS_PIR(name, help, field, unit_name) \
+ { name, help, OFFSET(field), AV_OPT_TYPE_INT, \
+ { .i64 = BSF_ELEMENT_PASS }, \
+ BSF_ELEMENT_PASS, BSF_ELEMENT_REMOVE, FLAGS, unit_name }, \
+ { "pass", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_PASS }, .flags = FLAGS, .unit = unit_name }, \
+ { "insert", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_INSERT }, .flags = FLAGS, .unit = unit_name }, \
+ { "remove", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_REMOVE }, .flags = FLAGS, .unit = unit_name }
+
+#define BSF_ELEMENT_OPTIONS_PIRE(name, help, field, unit_name) \
+ { name, help, OFFSET(field), AV_OPT_TYPE_INT, \
+ { .i64 = BSF_ELEMENT_PASS }, \
+ BSF_ELEMENT_PASS, BSF_ELEMENT_EXTRACT, FLAGS, unit_name }, \
+ { "pass", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_PASS }, .flags = FLAGS, .unit = unit_name }, \
+ { "insert", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_INSERT }, .flags = FLAGS, .unit = unit_name }, \
+ { "remove", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_REMOVE }, .flags = FLAGS, .unit = unit_name }, \
+ { "extract", NULL, 0, AV_OPT_TYPE_CONST, \
+ { .i64 = BSF_ELEMENT_EXTRACT }, .flags = FLAGS, .unit = unit_name } \
+
+
+#endif /* AVCODEC_CBS_BSF_H */
--
2.29.2
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