libavutil: add API for exporting video frame quantizers

This is intended to replace the deprecated the AV_FRAME_DATA_QP_TABLE*
API and extend it to a wider range of codecs.

In the future, it may also be extended to support other encoding
parameters such as motion vectors.

Additional changes by Anton Khirnov <anton@khirnov.net> with suggestions
by Lynne <dev@lynne.ee>.

Signed-off-by: Juan De León <juandl@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 79 insertions, 0 deletions

diff --git a/libavutil/video_enc_params.c b/libavutil/video_enc_params.c
new file mode 100644
index 0000000000..c46c0f1dc6
--- /dev/null
+++ b/libavutil/video_enc_params.c
@@ -0,0 +1,79 @@
+/*
+ * 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 <limits.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "buffer.h"
+#include "common.h"
+#include "frame.h"
+#include "mem.h"
+#include "video_enc_params.h"
+
+AVVideoEncParams *av_video_enc_params_alloc(enum AVVideoEncParamsType type,
+                                            unsigned int nb_blocks, size_t *out_size)
+{
+    AVVideoEncParams *par;
+    size_t size;
+
+    size = sizeof(*par);
+    if (nb_blocks > SIZE_MAX / sizeof(AVVideoBlockParams) ||
+        nb_blocks * sizeof(AVVideoBlockParams) > SIZE_MAX - size)
+        return NULL;
+    size += sizeof(AVVideoBlockParams) * nb_blocks;
+
+    par = av_mallocz(size);
+    if (!par)
+        return NULL;
+
+    par->type          = type;
+    par->nb_blocks     = nb_blocks;
+    par->block_size    = sizeof(AVVideoBlockParams);
+    par->blocks_offset = sizeof(*par);
+
+    if (out_size)
+        *out_size = size;
+
+    return par;
+}
+
+AVVideoEncParams*
+av_video_enc_params_create_side_data(AVFrame *frame, enum AVVideoEncParamsType type,
+                                     unsigned int nb_blocks)
+{
+    AVBufferRef      *buf;
+    AVVideoEncParams *par;
+    size_t size;
+
+    par = av_video_enc_params_alloc(type, nb_blocks, &size);
+    if (!par)
+        return NULL;
+    buf = av_buffer_create((uint8_t *)par, size, NULL, NULL, 0);
+    if (!buf) {
+        av_freep(&par);
+        return NULL;
+    }
+
+    if (!av_frame_new_side_data_from_buf(frame, AV_FRAME_DATA_VIDEO_ENC_PARAMS, buf)) {
+        av_buffer_unref(&buf);
+        return NULL;
+    }
+
+    return par;
+}