[FFmpeg-devel] [PATCH 1/2] avcodec: add an APV parser

* [FFmpeg-devel] [PATCH 1/2] avcodec: add an APV parser
@ 2025-04-27 21:15 James Almer
  2025-04-27 21:15 ` [FFmpeg-devel] [PATCH 2/2] avformat/apvdec: don't fill container level fields with codec level info James Almer
  2025-04-27 23:39 ` [FFmpeg-devel] [PATCH v2 1/2] avcodec: add an APV parser James Almer
  0 siblings, 2 replies; 4+ messages in thread
From: James Almer @ 2025-04-27 21:15 UTC (permalink / raw)
  To: ffmpeg-devel

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavcodec/Makefile     |   1 +
 libavcodec/apv_parser.c | 165 ++++++++++++++++++++++++++++++++++++++++
 libavcodec/parsers.c    |   1 +
 3 files changed, 167 insertions(+)
 create mode 100644 libavcodec/apv_parser.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index e674671460..cc142bbae2 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1198,6 +1198,7 @@ OBJS-$(CONFIG_AC3_PARSER)              += aac_ac3_parser.o ac3tab.o \
                                           ac3_channel_layout_tab.o
 OBJS-$(CONFIG_ADX_PARSER)              += adx_parser.o
 OBJS-$(CONFIG_AMR_PARSER)              += amr_parser.o
+OBJS-$(CONFIG_APV_PARSER)              += apv_parser.o
 OBJS-$(CONFIG_AV1_PARSER)              += av1_parser.o av1_parse.o
 OBJS-$(CONFIG_AVS2_PARSER)             += avs2.o avs2_parser.o
 OBJS-$(CONFIG_AVS3_PARSER)             += avs3_parser.o
diff --git a/libavcodec/apv_parser.c b/libavcodec/apv_parser.c
new file mode 100644
index 0000000000..53e5bb0921
--- /dev/null
+++ b/libavcodec/apv_parser.c
@@ -0,0 +1,165 @@
+/*
+ * 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 "avcodec.h"
+#include "bytestream.h"
+#include "apv.h"
+
+typedef struct APVParseContext {
+    uint8_t  profile_idc;
+    uint8_t  level_idc;
+
+    int      frame_width;
+    int      frame_height;
+
+    uint8_t  color_primaries;
+    uint8_t  transfer_characteristics;
+    uint8_t  matrix_coefficients;
+    uint8_t  full_range_flag;
+
+    enum AVPixelFormat pixel_format;
+} APVParseContext;
+
+static const enum AVPixelFormat apv_format_table[5][5] = {
+    { AV_PIX_FMT_GRAY8,    AV_PIX_FMT_GRAY10,     AV_PIX_FMT_GRAY12,     AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16 },
+    { 0 }, // 4:2:0 is not valid.
+    { AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV422P10,  AV_PIX_FMT_YUV422P12,  AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV422P16 },
+    { AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV444P10,  AV_PIX_FMT_YUV444P12,  AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV444P16 },
+    { AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUVA444P16 },
+};
+
+static int apv_extract_header_info(AVCodecParserContext *s, GetByteContext *gbc)
+{
+    APVParseContext *p = s->priv_data;
+    int pbu_type, chroma_format_idc, bit_depth_minus8;
+    int byte;
+
+    pbu_type = bytestream2_get_byte(gbc);
+    bytestream2_skip(gbc, 2);
+
+    if (bytestream2_get_byte(gbc))
+        return AVERROR_INVALIDDATA;
+
+    if (pbu_type != APV_PBU_PRIMARY_FRAME)
+        return AVERROR_INVALIDDATA;
+
+    p->profile_idc = bytestream2_get_byte(gbc);
+    p->level_idc   = bytestream2_get_byte(gbc);
+
+    if (bytestream2_get_byte(gbc) & 7)
+        return AVERROR_INVALIDDATA;
+
+    p->frame_width  = bytestream2_get_be24(gbc);
+    p->frame_height = bytestream2_get_be24(gbc);
+    if (p->frame_width  < 1 || p->frame_width  > 65536 ||
+        p->frame_height < 1 || p->frame_height > 65536)
+        return AVERROR_INVALIDDATA;
+
+    byte = bytestream2_get_byte(gbc);
+    chroma_format_idc = byte >> 4;
+    bit_depth_minus8  = byte & 0xf;
+
+    if (bit_depth_minus8 > 8)
+        return AVERROR_INVALIDDATA;
+    if (bit_depth_minus8 % 2) {
+        // Odd bit depths are technically valid but not useful here.
+        return AVERROR_INVALIDDATA;
+    }
+
+    switch (chroma_format_idc) {
+    case APV_CHROMA_FORMAT_400:
+    case APV_CHROMA_FORMAT_422:
+    case APV_CHROMA_FORMAT_444:
+    case APV_CHROMA_FORMAT_4444:
+        p->pixel_format = apv_format_table[chroma_format_idc][bit_depth_minus8 / 2];
+        break;
+    default:
+        return AVERROR_INVALIDDATA;
+    }
+
+    bytestream2_skip(gbc, 1);
+
+    if (bytestream2_get_be16(gbc))
+        return AVERROR_INVALIDDATA;
+
+    // color_description_present_flag
+    if (bytestream2_peek_byte(gbc) >> 7) {
+        unsigned color_description;
+
+        color_description           = bytestream2_get_be32(gbc);
+        p->color_primaries          = (color_description >> 23) & 0xff;
+        p->transfer_characteristics = (color_description >> 15) & 0xff;
+        p->matrix_coefficients      = (color_description >>  7) & 0xff;
+        p->full_range_flag          = (color_description >>  6) & 1;
+    } else {
+        p->color_primaries          = AVCOL_PRI_UNSPECIFIED;
+        p->transfer_characteristics = AVCOL_TRC_UNSPECIFIED;
+        p->matrix_coefficients      = AVCOL_SPC_UNSPECIFIED;
+        p->full_range_flag          = 0;
+    }
+
+    return 0;
+}
+
+static int parse(AVCodecParserContext *s,
+                 AVCodecContext *avctx,
+                 const uint8_t **poutbuf, int *poutbuf_size,
+                 const uint8_t *buf, int buf_size)
+{
+    APVParseContext *p = s->priv_data;
+    GetByteContext gbc;
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+
+    if (buf_size < 29)
+        return buf_size;
+
+    bytestream2_init(&gbc, buf, buf_size);
+
+    if (bytestream2_get_be32(&gbc) != APV_SIGNATURE)
+        return buf_size;
+    if (bytestream2_get_be32(&gbc) < 16) // pbu_size
+        return buf_size;
+    if (apv_extract_header_info(s, &gbc) < 0)
+        return buf_size;
+
+    s->key_frame                  = 1;
+    s->pict_type                  = AV_PICTURE_TYPE_I;
+    s->field_order                = AV_FIELD_UNKNOWN;
+    s->picture_structure          = AV_PICTURE_STRUCTURE_FRAME;
+    s->width                      = p->frame_width;
+    s->height                     = p->frame_height;
+    s->format                     = p->pixel_format;
+    avctx->profile                = p->profile_idc;
+    avctx->level                  = p->level_idc;
+    avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT;
+    avctx->color_primaries        = p->color_primaries;
+    avctx->color_trc              = p->transfer_characteristics;
+    avctx->colorspace             = p->matrix_coefficients;
+    avctx->color_range            = p->full_range_flag ? AVCOL_RANGE_JPEG
+                                                       : AVCOL_RANGE_MPEG;
+
+    return buf_size;
+}
+
+const AVCodecParser ff_apv_parser = {
+    .codec_ids    = { AV_CODEC_ID_APV },
+    .priv_data_size = sizeof(APVParseContext),
+    .parser_parse = parse,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 5387351fd0..21164f3751 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -25,6 +25,7 @@ extern const AVCodecParser ff_aac_latm_parser;
 extern const AVCodecParser ff_ac3_parser;
 extern const AVCodecParser ff_adx_parser;
 extern const AVCodecParser ff_amr_parser;
+extern const AVCodecParser ff_apv_parser;
 extern const AVCodecParser ff_av1_parser;
 extern const AVCodecParser ff_avs2_parser;
 extern const AVCodecParser ff_avs3_parser;
-- 
2.49.0

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