[FFmpeg-devel] [PATCH] avcodec: add exr format parser
Paul B Mahol
onemda at gmail.com
Wed Feb 17 15:30:45 EET 2021
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/Makefile | 1 +
libavcodec/exr_parser.c | 217 ++++++++++++++++++++++++++++++++++++++++
libavcodec/parsers.c | 1 +
3 files changed, 219 insertions(+)
create mode 100644 libavcodec/exr_parser.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 5fb735f129..82d1f15b40 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1095,6 +1095,7 @@ OBJS-$(CONFIG_DVAUDIO_PARSER) += dvaudio_parser.o
OBJS-$(CONFIG_DVBSUB_PARSER) += dvbsub_parser.o
OBJS-$(CONFIG_DVD_NAV_PARSER) += dvd_nav_parser.o
OBJS-$(CONFIG_DVDSUB_PARSER) += dvdsub_parser.o
+OBJS-$(CONFIG_EXR_PARSER) += exr_parser.o
OBJS-$(CONFIG_FLAC_PARSER) += flac_parser.o flacdata.o flac.o
OBJS-$(CONFIG_G723_1_PARSER) += g723_1_parser.o
OBJS-$(CONFIG_G729_PARSER) += g729_parser.o
diff --git a/libavcodec/exr_parser.c b/libavcodec/exr_parser.c
new file mode 100644
index 0000000000..93833cd23d
--- /dev/null
+++ b/libavcodec/exr_parser.c
@@ -0,0 +1,217 @@
+/*
+ * EXR parser
+ * Copyright (c) 2020 Paul B Mahol
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * EXR parser
+ */
+
+#include "libavutil/bswap.h"
+#include "libavutil/intreadwrite.h"
+#include "parser.h"
+
+typedef struct EXRParseContext {
+ ParseContext pc;
+
+ int flags;
+ uint32_t w, h;
+ uint32_t tile_w, tile_h;
+ int64_t skip_bytes;
+ uint64_t bytes_read;
+ int nb_offsets;
+ unsigned curr_offset;
+ unsigned offset_index;
+ uint64_t max_offset;
+ int compression;
+
+ int exr_state;
+ uint8_t key[256];
+ unsigned key_index;
+ uint8_t type[256];
+ unsigned type_index;
+ uint32_t size;
+ unsigned size_index;
+ uint8_t value[256];
+ uint32_t value_index;
+} EXRParseContext;
+
+static int exr_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+ const uint8_t **poutbuf, int *poutbuf_size,
+ const uint8_t *buf, int buf_size)
+{
+ EXRParseContext *exr = s->priv_data;
+ uint64_t state = exr->pc.state64;
+ int next = END_NOT_FOUND, i = 0;
+
+ s->pict_type = AV_PICTURE_TYPE_I;
+ s->key_frame = 1;
+
+ *poutbuf_size = 0;
+ *poutbuf = NULL;
+
+ if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
+ next = buf_size;
+ } else {
+ for (; i < buf_size; i++) {
+ exr->bytes_read++;
+ state = (state << 8) | buf[i];
+
+ if (exr->skip_bytes > 0 && exr->exr_state == 0) {
+ exr->skip_bytes--;
+ if (exr->skip_bytes == 0) {
+ next = i + 1;
+ exr->bytes_read = 0;
+ break;
+ }
+ } else if (exr->exr_state == 1) {
+ exr->key[exr->key_index++] = buf[i];
+ if (exr->key_index >= 255) {
+ exr->exr_state = 0;
+ exr->key_index = 0;
+ memset(exr->key, 0, sizeof(exr->key));
+ goto new_state;
+ }
+
+ if (!buf[i] && exr->key_index == 1) {
+ exr->exr_state = 5;
+ if (!(exr->flags & 0x020000)) {
+ switch (exr->compression) {
+ case 5:
+ case 3:
+ exr->nb_offsets = (exr->nb_offsets + 15) >> 4;
+ break;
+ case 4:
+ case 6:
+ case 7:
+ exr->nb_offsets = (exr->nb_offsets + 31) >> 5;
+ break;
+ default:
+ break;
+ }
+ } else if (exr->tile_w && exr->tile_h) {
+ exr->nb_offsets = ((exr->w + exr->tile_w - 1) / exr->tile_w) *
+ ((exr->h + exr->tile_h - 1) / exr->tile_h);
+ }
+ exr->curr_offset = 0;
+ exr->offset_index = 0;
+ exr->max_offset = 0;
+ } else if (!buf[i]) {
+ exr->exr_state = 2;
+ }
+ } else if (exr->exr_state == 2) {
+ exr->type[exr->type_index++] = buf[i];
+ if (exr->type_index >= 255) {
+ exr->exr_state = 0;
+ exr->type_index = 0;
+ memset(exr->type, 0, sizeof(exr->type));
+ exr->key_index = 0;
+ memset(exr->key, 0, sizeof(exr->key));
+ goto new_state;
+ }
+
+ if (!buf[i]) {
+ exr->exr_state = 3;
+ exr->size_index = 0;
+ exr->size = 0;
+ }
+ } else if (exr->exr_state == 3) {
+ exr->size = (exr->size << 8) | buf[i];
+ exr->size_index++;
+ if (exr->size_index == 4) {
+ exr->exr_state = 4;
+ }
+ } else if (exr->exr_state == 4) {
+ if (exr->value_index < 255)
+ exr->value[exr->value_index] = buf[i];
+ exr->value_index++;
+ if (exr->value_index == av_bswap32(exr->size)) {
+ if (!strcmp(exr->key, "dataWindow") &&
+ !strcmp(exr->type, "box2i")) {
+ exr->w = AV_RL32(exr->value + 8) + 1 - AV_RL32(exr->value + 0);
+ exr->h = AV_RL32(exr->value + 12) + 1 - AV_RL32(exr->value + 4);
+ exr->nb_offsets = exr->h;
+ } else if (!strcmp(exr->key, "compression") &&
+ !strcmp(exr->type, "compression")) {
+ exr->compression = exr->value[0];
+ } else if (!strcmp(exr->key, "tiles") &&
+ !strcmp(exr->type, "tiledesc")) {
+ exr->tile_w = AV_RL32(exr->value + 0);
+ exr->tile_h = AV_RL32(exr->value + 4);
+ }
+ exr->exr_state = 1;
+ exr->size = 0;
+ exr->key_index = 0;
+ exr->type_index = 0;
+ exr->value_index = 0;
+ memset(exr->key, 0, sizeof(exr->key));
+ memset(exr->type, 0, sizeof(exr->type));
+ }
+ } else if (exr->exr_state == 5) {
+ exr->offset_index++;
+ if (exr->offset_index == 8) {
+ uint64_t new_offset = av_bswap64(state);
+
+ exr->curr_offset++;
+ exr->offset_index = 0;
+ if (exr->max_offset < new_offset)
+ exr->max_offset = new_offset;
+ if (exr->curr_offset >= exr->nb_offsets) {
+ exr->curr_offset = 0;
+ exr->exr_state = 6;
+ }
+ }
+ } else if (exr->exr_state == 6) {
+ if (exr->bytes_read == exr->max_offset + 8 + (!!(exr->flags & 0x020000)) * 12) {
+ exr->skip_bytes = av_bswap32(state & 0xFFFFFFFF);
+ exr->bytes_read = 0;
+ exr->exr_state = 0;
+ exr->max_offset = 0;
+ exr->nb_offsets = 0;
+ }
+ }
+
+new_state:
+ if (exr->exr_state == 0 && ((state & 0xFFFFFFFFFF000000LL) == 0x762F310102000000LL)) {
+ exr->flags = state & 0xFFFFFF;
+ exr->exr_state = 1;
+ }
+ }
+
+ exr->pc.state64 = state;
+ if (ff_combine_frame(&exr->pc, next, &buf, &buf_size) < 0) {
+ *poutbuf = NULL;
+ *poutbuf_size = 0;
+ return buf_size;
+ }
+ }
+
+ *poutbuf = buf;
+ *poutbuf_size = buf_size;
+
+ return next;
+}
+
+AVCodecParser ff_exr_parser = {
+ .codec_ids = { AV_CODEC_ID_EXR },
+ .priv_data_size = sizeof(EXRParseContext),
+ .parser_parse = exr_parse,
+ .parser_close = ff_parse_close,
+};
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 61af22b2d5..e5b3f998df 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -43,6 +43,7 @@ extern AVCodecParser ff_dvaudio_parser;
extern AVCodecParser ff_dvbsub_parser;
extern AVCodecParser ff_dvdsub_parser;
extern AVCodecParser ff_dvd_nav_parser;
+extern AVCodecParser ff_exr_parser;
extern AVCodecParser ff_flac_parser;
extern AVCodecParser ff_g723_1_parser;
extern AVCodecParser ff_g729_parser;
--
2.17.1
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