[FFmpeg-devel] [PATCH v3 3/5] avcodec/avs2_parser: parse more info
Zhao Zhili
quinkblack at foxmail.com
Mon Jun 13 06:36:34 EEST 2022
Including video resolution, framerate and picture type, etc.
Signed-off-by: Zhao Zhili <zhilizhao at tencent.com>
---
libavcodec/Makefile | 2 +-
libavcodec/avs2.c | 42 ++++++++++++++++
libavcodec/avs2.h | 10 ++++
libavcodec/avs2_parser.c | 105 +++++++++++++++++++++++++++++++++++++++
4 files changed, 158 insertions(+), 1 deletion(-)
create mode 100644 libavcodec/avs2.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 3b8f7b5e01..6cc6f8437c 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1114,7 +1114,7 @@ OBJS-$(CONFIG_AC3_PARSER) += aac_ac3_parser.o ac3tab.o \
OBJS-$(CONFIG_ADX_PARSER) += adx_parser.o adx.o
OBJS-$(CONFIG_AMR_PARSER) += amr_parser.o
OBJS-$(CONFIG_AV1_PARSER) += av1_parser.o
-OBJS-$(CONFIG_AVS2_PARSER) += avs2_parser.o
+OBJS-$(CONFIG_AVS2_PARSER) += avs2.o avs2_parser.o
OBJS-$(CONFIG_AVS3_PARSER) += avs3_parser.o
OBJS-$(CONFIG_BMP_PARSER) += bmp_parser.o
OBJS-$(CONFIG_CAVSVIDEO_PARSER) += cavs_parser.o
diff --git a/libavcodec/avs2.c b/libavcodec/avs2.c
new file mode 100644
index 0000000000..ead8687d0a
--- /dev/null
+++ b/libavcodec/avs2.c
@@ -0,0 +1,42 @@
+/*
+ * AVS2 related definitions
+ *
+ * Copyright (C) 2022 Zhao Zhili, <zhilizhao at tencent.com>
+ *
+ * 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 "avs2.h"
+
+const AVRational ff_avs2_frame_rate_tab[16] = {
+ { 0 , 0 }, // forbid
+ { 24000, 1001},
+ { 24 , 1 },
+ { 25 , 1 },
+ { 30000, 1001},
+ { 30 , 1 },
+ { 50 , 1 },
+ { 60000, 1001},
+ { 60 , 1 },
+ { 100 , 1 },
+ { 120 , 1 },
+ { 200 , 1 },
+ { 240 , 1 },
+ { 300 , 1 },
+ { 0 , 0 }, // reserved
+ { 0 , 0 } // reserved
+};
diff --git a/libavcodec/avs2.h b/libavcodec/avs2.h
index f342ba52a0..544cf502d7 100644
--- a/libavcodec/avs2.h
+++ b/libavcodec/avs2.h
@@ -23,6 +23,8 @@
#ifndef AVCODEC_AVS2_H
#define AVCODEC_AVS2_H
+#include "libavutil/rational.h"
+
#define AVS2_SLICE_MAX_START_CODE 0x000001AF
enum {
@@ -38,4 +40,12 @@ enum {
#define AVS2_ISPIC(x) ((x) == AVS2_INTRA_PIC_START_CODE || (x) == AVS2_INTER_PIC_START_CODE)
#define AVS2_ISUNIT(x) ((x) == AVS2_SEQ_START_CODE || AVS2_ISPIC(x))
+enum AVS2Profile {
+ AVS2_PROFILE_MAIN_PIC = 0x12,
+ AVS2_PROFILE_MAIN = 0x20,
+ AVS2_PROFILE_MAIN10 = 0x22,
+};
+
+extern const AVRational ff_avs2_frame_rate_tab[16];
+
#endif
diff --git a/libavcodec/avs2_parser.c b/libavcodec/avs2_parser.c
index 71cf442903..0350517493 100644
--- a/libavcodec/avs2_parser.c
+++ b/libavcodec/avs2_parser.c
@@ -19,7 +19,9 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include "libavutil/avutil.h"
#include "avs2.h"
+#include "get_bits.h"
#include "parser.h"
static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
@@ -58,6 +60,107 @@ static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_siz
return END_NOT_FOUND;
}
+static void parse_avs2_seq_header(AVCodecParserContext *s, const uint8_t *buf,
+ int buf_size, AVCodecContext *avctx)
+{
+ GetBitContext gb;
+ int profile, level;
+ int width, height;
+ int chroma, sample_precision, encoding_precision = 1;
+ // sample_precision and encoding_precision is 3 bits
+ static const uint8_t precision[8] = { 0, 8, 10 };
+ unsigned aspect_ratio;
+ unsigned frame_rate_code;
+ int low_delay;
+ // update buf_size_min if parse more deeper
+ const int buf_size_min = 15;
+
+ if (buf_size < buf_size_min)
+ return;
+
+ init_get_bits8(&gb, buf, buf_size_min);
+
+ s->key_frame = 1;
+ s->pict_type = AV_PICTURE_TYPE_I;
+
+ profile = get_bits(&gb, 8);
+ level = get_bits(&gb, 8);
+
+ // progressive_sequence u(1)
+ // field_coded_sequence u(1)
+ skip_bits(&gb, 2);
+
+ width = get_bits(&gb, 14);
+ height = get_bits(&gb, 14);
+
+ chroma = get_bits(&gb, 2);
+ sample_precision = get_bits(&gb, 3);
+ if (profile == AVS2_PROFILE_MAIN10)
+ encoding_precision = get_bits(&gb, 3);
+
+ aspect_ratio = get_bits(&gb, 4);
+ frame_rate_code = get_bits(&gb, 4);
+
+ // bit_rate_lower u(18)
+ // marker_bit f(1)
+ // bit_rate_upper u(12)
+ skip_bits(&gb, 31);
+
+ low_delay = get_bits(&gb, 1);
+
+ s->width = width;
+ s->height = height;
+ s->coded_width = FFALIGN(width, 8);
+ s->coded_height = FFALIGN(height, 8);
+ avctx->framerate.num = avctx->time_base.den =
+ ff_avs2_frame_rate_tab[frame_rate_code].num;
+ avctx->framerate.den = avctx->time_base.num =
+ ff_avs2_frame_rate_tab[frame_rate_code].den;
+ avctx->has_b_frames = FFMAX(avctx->has_b_frames, !low_delay);
+
+ av_log(avctx, AV_LOG_DEBUG,
+ "AVS2 parse seq HDR: profile %x, level %x, "
+ "width %d, height %d, "
+ "chroma %d, sample_precision %d bits, encoding_precision %d bits, "
+ "aspect_ratio 0x%x, framerate %d/%d, low_delay %d\n",
+ profile, level,
+ width, height,
+ chroma, precision[sample_precision], precision[encoding_precision],
+ aspect_ratio, avctx->framerate.num, avctx->framerate.den, low_delay);
+}
+
+static void parse_avs2_units(AVCodecParserContext *s, const uint8_t *buf,
+ int buf_size, AVCodecContext *avctx)
+{
+ if (buf_size < 5)
+ return;
+
+ if (!(buf[0] == 0x0 && buf[1] == 0x0 && buf[2] == 0x1))
+ return;
+
+ switch (buf[3]) {
+ case AVS2_SEQ_START_CODE:
+ parse_avs2_seq_header(s, buf + 4, buf_size - 4, avctx);
+ return;
+ case AVS2_INTRA_PIC_START_CODE:
+ s->key_frame = 1;
+ s->pict_type = AV_PICTURE_TYPE_I;
+ return;
+ case AVS2_INTER_PIC_START_CODE:
+ s->key_frame = 0;
+ if (buf_size > 9) {
+ int pic_code_type = buf[8] & 0x3;
+ if (pic_code_type == 1)
+ s->pict_type = AV_PICTURE_TYPE_P;
+ else if (pic_code_type == 3)
+ s->pict_type = AV_PICTURE_TYPE_S;
+ else
+ s->pict_type = AV_PICTURE_TYPE_B;
+ }
+ return;
+ }
+}
+
static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
@@ -76,6 +179,8 @@ static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx,
}
}
+ parse_avs2_units(s, buf, buf_size, avctx);
+
*poutbuf = buf;
*poutbuf_size = buf_size;
--
2.35.3
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