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-rw-r--r--libavcodec/vp9_parser.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/libavcodec/vp9_parser.c b/libavcodec/vp9_parser.c
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+++ b/libavcodec/vp9_parser.c
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+/*
+ * VP9 compatible video decoder
+ *
+ * Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com>
+ * Copyright (C) 2013 Clément Bœsch <u pkh me>
+ *
+ * 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 "libavutil/intreadwrite.h"
+#include "parser.h"
+
+typedef struct VP9ParseContext {
+ int n_frames; // 1-8
+ int size[8];
+ int64_t pts;
+} VP9ParseContext;
+
+static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size)
+{
+ VP9ParseContext *s = ctx->priv_data;
+
+ if (buf[0] & 0x4) {
+ ctx->pict_type = AV_PICTURE_TYPE_P;
+ ctx->key_frame = 0;
+ } else {
+ ctx->pict_type = AV_PICTURE_TYPE_I;
+ ctx->key_frame = 1;
+ }
+
+ if (buf[0] & 0x2) {
+ if (ctx->pts == AV_NOPTS_VALUE)
+ ctx->pts = s->pts;
+ s->pts = AV_NOPTS_VALUE;
+ } else {
+ s->pts = ctx->pts;
+ ctx->pts = AV_NOPTS_VALUE;
+ }
+}
+
+static int parse(AVCodecParserContext *ctx,
+ AVCodecContext *avctx,
+ const uint8_t **out_data, int *out_size,
+ const uint8_t *data, int size)
+{
+ VP9ParseContext *s = ctx->priv_data;
+ int full_size = size;
+ int marker;
+
+ if (size <= 0) {
+ *out_size = 0;
+ *out_data = data;
+
+ return 0;
+ }
+
+ if (s->n_frames > 0) {
+ *out_data = data;
+ *out_size = s->size[--s->n_frames];
+ parse_frame(ctx, *out_data, *out_size);
+
+ return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */;
+ }
+
+ marker = data[size - 1];
+ if ((marker & 0xe0) == 0xc0) {
+ int nbytes = 1 + ((marker >> 3) & 0x3);
+ int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
+
+ if (size >= idx_sz && data[size - idx_sz] == marker) {
+ const uint8_t *idx = data + size + 1 - idx_sz;
+ int first = 1;
+
+ switch (nbytes) {
+#define case_n(a, rd) \
+ case a: \
+ while (n_frames--) { \
+ unsigned sz = rd; \
+ idx += a; \
+ if (sz > size) { \
+ s->n_frames = 0; \
+ *out_size = size; \
+ *out_data = data; \
+ av_log(avctx, AV_LOG_ERROR, \
+ "Superframe packet size too big: %u > %d\n", \
+ sz, size); \
+ return full_size; \
+ } \
+ if (first) { \
+ first = 0; \
+ *out_data = data; \
+ *out_size = sz; \
+ s->n_frames = n_frames; \
+ } else { \
+ s->size[n_frames] = sz; \
+ } \
+ data += sz; \
+ size -= sz; \
+ } \
+ parse_frame(ctx, *out_data, *out_size); \
+ return *out_size
+
+ case_n(1, *idx);
+ case_n(2, AV_RL16(idx));
+ case_n(3, AV_RL24(idx));
+ case_n(4, AV_RL32(idx));
+ }
+ }
+ }
+
+ *out_data = data;
+ *out_size = size;
+ parse_frame(ctx, data, size);
+
+ return size;
+}
+
+AVCodecParser ff_vp9_parser = {
+ .codec_ids = { AV_CODEC_ID_VP9 },
+ .priv_data_size = sizeof(VP9ParseContext),
+ .parser_parse = parse,
+};