[FFmpeg-devel] [PATCH v3 3/5] avcodec/avs2_parser: parse more info
"zhilizhao(赵志立)"
quinkblack at foxmail.com
Tue Jun 21 11:25:17 EEST 2022
> On Jun 21, 2022, at 10:45 AM, hwren <hwrenx at 126.com> wrote:
>
> At 2022-06-13 11:36:34, "Zhao Zhili" <quinkblack at foxmail.com> wrote:
>> 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
>> +};
>
> That table seems to appear only in avs2 decoder. If so, they are supposed to be declared in libdavs2.c.
> If not, please point out the usage of this separate source file.
It’s used in this patch, parse_avs2_seq_header().
>
> Persionally, the frame_rate table can be used in both encoder and decoder. So it is what should be
> defined in the avs2.h (with related enc/dec changes).
It’s declared in avs2.h, so it can be used by enc/dec.
It’s defined in .c to reduce binary size.
>
>> 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))
>>
>
> Same as above. Mentioned definitions now are only used in avs2_parser.c. If so, they are supposed to be
> kept in avs2_parser.c.
It’s not the same as ff_avs2_frame_rate_tab. Firstly, define enum
and macros doesn’t generate binary. Secondly, they are be used
by avs2 parser/decoder/encoder and so on, the same as avs3.h.
They are only used by avs2 parser now, but they are handy when debug
decoder, for example, and future proof.
>
>
>> +enum AVS2Profile {
>> + AVS2_PROFILE_MAIN_PIC = 0x12,
>> + AVS2_PROFILE_MAIN = 0x20,
>> + AVS2_PROFILE_MAIN10 = 0x22,
>> +};
>
> Not mentioned elsewhere. If they are to work in the encoder/decoder, please package them with related changes.
AVS2_PROFILE_MAIN10 is used in this patch.
>
>> +
>> +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
>
>
> Best Regards,
> Huiwen Ren
>
>>
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>
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