[FFmpeg-devel] [PATCH v1 2/4] lavc/avs3_paeser: add avs3 parser

hwrenx at 126.com hwrenx at 126.com
Sat Jun 20 04:45:50 EEST 2020


From: hwren <hwrenx at 126.com>

Signed-off-by: hbj <hanbj at pku.edu.cn>
Signed-off-by: hwren <hwrenx at 126.com>
---
 libavcodec/Makefile      |   1 +
 libavcodec/avs3_parser.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/parsers.c     |   1 +
 3 files changed, 186 insertions(+)
 create mode 100644 libavcodec/avs3_parser.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 5a6ea59..f151277 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1053,6 +1053,7 @@ OBJS-$(CONFIG_AC3_PARSER)              += ac3tab.o aac_ac3_parser.o
 OBJS-$(CONFIG_ADX_PARSER)              += adx_parser.o adx.o
 OBJS-$(CONFIG_AV1_PARSER)              += av1_parser.o av1_parse.o
 OBJS-$(CONFIG_AVS2_PARSER)             += avs2_parser.o
+OBJS-$(CONFIG_AVS3_PARSER)             += avs3_parser.o
 OBJS-$(CONFIG_BMP_PARSER)              += bmp_parser.o
 OBJS-$(CONFIG_CAVSVIDEO_PARSER)        += cavs_parser.o
 OBJS-$(CONFIG_COOK_PARSER)             += cook_parser.o
diff --git a/libavcodec/avs3_parser.c b/libavcodec/avs3_parser.c
new file mode 100644
index 0000000..7a7f826
--- /dev/null
+++ b/libavcodec/avs3_parser.c
@@ -0,0 +1,184 @@
+/*
+ * AVS3-P2/IEEE1857.10 video parser.
+ * Copyright (c) 2020 Zhenyu Wang <wangzhenyu at pkusz.edu.cn>
+ *                    Bingjie Han <hanbj at pkusz.edu.cn>
+ *                    Huiwen Ren  <hwrenx at gmail.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 "parser.h"
+
+#define SLICE_MAX_START_CODE    0x000001af
+
+#define ISPIC(x)  ((x) == 0xB3 || (x) == 0xB6)
+#define ISUNIT(x) ((x) == 0xB0 || ISPIC(x))
+
+static av_cold int avs3_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
+{
+    int pic_found  = pc->frame_start_found;
+    uint32_t state = pc->state;
+    int cur = 0;
+
+    if (!pic_found) {
+        for (; cur < buf_size; ++cur) {
+            state = (state<<8) | buf[cur];
+            if (ISPIC(buf[cur])){
+                ++cur;
+                pic_found = 1;
+                break;
+            }
+        }
+    }
+
+    if (pic_found) {
+        if (!buf_size)
+            return END_NOT_FOUND;
+        for (; cur < buf_size; ++cur) {
+            state = (state << 8) | buf[cur];
+            if ((state & 0xFFFFFF00) == 0x100 && ISUNIT(state & 0xFF)) {
+                pc->frame_start_found = 0;
+                pc->state = -1;
+                return cur - 3;
+            }
+        }
+    }
+
+    pc->frame_start_found = pic_found;
+    pc->state = state;
+
+    return END_NOT_FOUND;
+}
+
+static unsigned int read_bits(const char** ppbuf, int *pidx, int bits) 
+{
+    const char* p = *ppbuf;
+    int idx = *pidx;
+    unsigned int val = 0;
+    
+    while (bits) {
+        bits--;
+        val = (val << 1) | (((*p) >> idx) & 0x1);
+        if (--idx < 0) {
+            idx = 7;
+            p++;
+        }
+    }
+
+    *ppbuf = p;
+    *pidx = idx;
+
+    return val;
+}
+
+static void parse_avs3_nal_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) {
+        if (buf[3] == 0xB0) {
+            static const int avs3_fps_num[9] = {0, 240000, 24, 25, 30000, 30, 50, 60000, 60 };
+            static const int avs3_fps_den[9] = {1,   1001,  1,  1,  1001,  1,  1,  1001,  1 };
+            int profile,ratecode;
+            const char* p = buf + 4;
+            int idx = 7;
+            
+            s->key_frame = 1;
+            s->pict_type = AV_PICTURE_TYPE_I;
+
+            profile = read_bits(&p, &idx, 8);
+            // level(8) + progressive(1) + field(1) + library(2) + resv(1) + width(14) + resv(1) + height(14) + chroma(2) + sampe_precision(3)
+            read_bits(&p, &idx, 47); 
+        
+            if (profile == 0x22) {
+                avctx->pix_fmt = read_bits(&p, &idx, 3) == 1 ? AV_PIX_FMT_YUV420P : AV_PIX_FMT_YUV420P10LE;
+            } 
+
+            // resv(1) + aspect(4)
+            read_bits(&p, &idx, 5);
+
+            ratecode = read_bits(&p, &idx, 4);
+
+            // resv(1) + bitrate_low(18) + resv(1) + bitrate_high(12)
+            read_bits(&p, &idx, 32);
+
+            avctx->has_b_frames = !read_bits(&p, &idx, 1);
+
+            avctx->framerate.num = avctx->time_base.den = avs3_fps_num[ratecode];
+            avctx->framerate.den = avctx->time_base.num = avs3_fps_den[ratecode];
+
+            s->width  = s->coded_width = avctx->width;
+            s->height = s->coded_height = avctx->height;
+            
+            av_log(avctx, AV_LOG_DEBUG,
+                       "avs3 parse seq hdr: profile %d; coded wxh: %dx%d; "
+                       "frame_rate_code %d\n", profile, avctx->width, avctx->height, ratecode);
+
+        } else if (buf[3] == 0xB3) {
+            s->key_frame = 1;
+            s->pict_type = AV_PICTURE_TYPE_I;
+        } else if (buf[3] == 0xB6){
+            s->key_frame = 0;
+            if (buf_size > 9) {
+                int pic_code_type = buf[8] & 0x3;
+                if (pic_code_type == 1 || pic_code_type == 3) {
+                    s->pict_type = AV_PICTURE_TYPE_P;
+                } else {
+                    s->pict_type = AV_PICTURE_TYPE_B;
+                }
+            }
+        }
+    }
+}
+
+
+static int avs3_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                      const uint8_t **poutbuf, int *poutbuf_size,
+                      const uint8_t *buf, int buf_size)
+{
+    ParseContext *pc = s->priv_data;
+    int next;
+
+    if (s->flags & PARSER_FLAG_COMPLETE_FRAMES)  {
+        next = buf_size;
+    } else {
+        next = avs3_find_frame_end(pc, buf, buf_size);
+        if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
+            *poutbuf = NULL;
+            *poutbuf_size = 0;
+            return buf_size;
+        }
+    }
+
+    parse_avs3_nal_units(s, buf, buf_size, avctx);
+    
+    *poutbuf = buf;
+    *poutbuf_size = buf_size;
+
+    return next;
+}
+
+AVCodecParser ff_avs3_parser = {
+    .codec_ids      = { AV_CODEC_ID_AVS3 },
+    .priv_data_size = sizeof(ParseContext),
+    .parser_parse   = avs3_parse,
+    .parser_close   = ff_parse_close,
+    .split          = ff_mpeg4video_split,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 7d75cea..aab1d5e 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -28,6 +28,7 @@ extern AVCodecParser ff_ac3_parser;
 extern AVCodecParser ff_adx_parser;
 extern AVCodecParser ff_av1_parser;
 extern AVCodecParser ff_avs2_parser;
+extern AVCodecParser ff_avs3_parser;
 extern AVCodecParser ff_bmp_parser;
 extern AVCodecParser ff_cavsvideo_parser;
 extern AVCodecParser ff_cook_parser;
-- 
2.7.4



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