[FFmpeg-devel] [PATCH 1/2] libavcodec/pgxdec: Add PGX decoder
gautamramk at gmail.com
gautamramk at gmail.com
Sat Jun 27 10:05:17 EEST 2020
From: Gautam Ramakrishnan <gautamramk at gmail.com>
This patch adds a pgx decoder.
---
Changelog | 1 +
doc/general.texi | 2 +
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/codec_desc.c | 7 ++
libavcodec/codec_id.h | 1 +
libavcodec/pgxdec.c | 184 ++++++++++++++++++++++++++++++++++++++++
libavcodec/version.h | 2 +-
8 files changed, 198 insertions(+), 1 deletion(-)
create mode 100644 libavcodec/pgxdec.c
diff --git a/Changelog b/Changelog
index a60e7d2eb8..1bb9931c0d 100644
--- a/Changelog
+++ b/Changelog
@@ -4,6 +4,7 @@ releases are sorted from youngest to oldest.
version <next>:
- AudioToolbox output device
- MacCaption demuxer
+- PGX decoder
version 4.3:
diff --git a/doc/general.texi b/doc/general.texi
index ea34b963b5..53d556c56c 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -751,6 +751,8 @@ following image formats are supported:
@tab Portable GrayMap image
@item PGMYUV @tab X @tab X
@tab PGM with U and V components in YUV 4:2:0
+ at item PGX @tab @tab X
+ @tab PGX file decoder
@item PIC @tab @tab X
@tab Pictor/PC Paint
@item PNG @tab X @tab X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 5a6ea59715..12aa43fe51 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -536,6 +536,7 @@ OBJS-$(CONFIG_PGM_ENCODER) += pnmenc.o
OBJS-$(CONFIG_PGMYUV_DECODER) += pnmdec.o pnm.o
OBJS-$(CONFIG_PGMYUV_ENCODER) += pnmenc.o
OBJS-$(CONFIG_PGSSUB_DECODER) += pgssubdec.o
+OBJS-$(CONFIG_PGX_DECODER) += pgxdec.o
OBJS-$(CONFIG_PICTOR_DECODER) += pictordec.o cga_data.o
OBJS-$(CONFIG_PIXLET_DECODER) += pixlet.o
OBJS-$(CONFIG_PJS_DECODER) += textdec.o ass.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index fa0c08d42e..a5048290f7 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -238,6 +238,7 @@ extern AVCodec ff_pgm_encoder;
extern AVCodec ff_pgm_decoder;
extern AVCodec ff_pgmyuv_encoder;
extern AVCodec ff_pgmyuv_decoder;
+extern AVCodec ff_pgx_decoder;
extern AVCodec ff_pictor_decoder;
extern AVCodec ff_pixlet_decoder;
extern AVCodec ff_png_encoder;
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 9f8847544f..67e0a3055c 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1405,6 +1405,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("AVS2-P2/IEEE1857.4"),
.props = AV_CODEC_PROP_LOSSY,
},
+ {
+ .id = AV_CODEC_ID_PGX,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "pgx",
+ .long_name = NULL_IF_CONFIG_SMALL("PGX (JPEG2000 Test Format)"),
+ .props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
+ },
{
.id = AV_CODEC_ID_Y41P,
.type = AVMEDIA_TYPE_VIDEO,
diff --git a/libavcodec/codec_id.h b/libavcodec/codec_id.h
index d885962c9c..896ecb0ce0 100644
--- a/libavcodec/codec_id.h
+++ b/libavcodec/codec_id.h
@@ -241,6 +241,7 @@ enum AVCodecID {
AV_CODEC_ID_SCREENPRESSO,
AV_CODEC_ID_RSCC,
AV_CODEC_ID_AVS2,
+ AV_CODEC_ID_PGX,
AV_CODEC_ID_Y41P = 0x8000,
AV_CODEC_ID_AVRP,
diff --git a/libavcodec/pgxdec.c b/libavcodec/pgxdec.c
new file mode 100644
index 0000000000..df5f5028cd
--- /dev/null
+++ b/libavcodec/pgxdec.c
@@ -0,0 +1,184 @@
+/*
+ * PGX image format
+ * Copyright (c) 2020 Gautam Ramakrishnan
+ *
+ * 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 "internal.h"
+#include "bytestream.h"
+
+typedef struct PGXContext {
+ GetByteContext g;
+ int depth;
+ int sign;
+ int width;
+ int height;
+} PGXContext;
+
+static int pgx_get_number(AVCodecContext *avctx, PGXContext * const s) {
+ int ret = -1;
+ char digit;
+
+ while (1) {
+ if (!bytestream2_get_bytes_left(&s->g))
+ return AVERROR_INVALIDDATA;
+ digit = bytestream2_get_byte(&s->g);
+ if (digit == ' ' || digit == 0xA || digit == 0xD) {
+ break;
+ } else if (digit < '0' || digit > '9') {
+ return AVERROR_INVALIDDATA;
+ }
+ if (ret < 0)
+ ret = 0;
+ ret = 10 * ret + (digit - '0');
+ }
+
+ if (ret >= 0)
+ return ret;
+ return AVERROR_INVALIDDATA;
+}
+
+static int ff_pgx_decode_header(AVCodecContext *avctx, PGXContext * s)
+{
+ const char *header_start = "PG ML ";
+ int byte;
+
+ if (bytestream2_get_bytes_left(&s->g) < 13) {
+ return AVERROR_INVALIDDATA;
+ }
+ // Checks whether file starts with "PG ML "
+ if (memcmp(header_start, s->g.buffer, 6))
+ return AVERROR_INVALIDDATA;
+ bytestream2_skip(&s->g, 6);
+
+ // Is the component signed?
+ byte = bytestream2_peek_byte(&s->g);
+ if (byte == '+') {
+ s->sign = 0;
+ bytestream2_skip(&s->g, 1);
+ } else if (byte == '-') {
+ s->sign = 1;
+ bytestream2_skip(&s->g, 1);
+ }
+
+ if (bytestream2_peek_byte(&s->g) == ' ')
+ bytestream2_skip(&s->g, 1);
+ s->depth = pgx_get_number(avctx, s);
+ s->width = pgx_get_number(avctx, s);
+ s->height = pgx_get_number(avctx, s);
+ if (bytestream2_peek_byte(&s->g) == 0xA)
+ bytestream2_skip(&s->g, 1);
+ return 0;
+}
+
+static inline int write_frame_8(AVPacket *avpkt, AVFrame *frame, PGXContext * const s)
+{
+ int i, j;
+ for (i = 0; i < s->height; i++) {
+ uint8_t *line = frame->data[0] + i * frame->linesize[0];
+ for (j = 0; j < s->width; j++) {
+ int val;
+ if (bytestream2_get_bytes_left(&s->g) < 1)
+ return AVERROR_INVALIDDATA;
+ if (s->sign) {
+ val = bytestream2_get_byte(&s->g) + (1 << (s->depth - 1));
+ val <<= (8 - s->depth);
+ *(line + j) = val;
+ } else {
+ val = bytestream2_get_byteu(&s->g);
+ val <<= (8 - s->depth);
+ *(line + j) = val;
+ }
+ }
+ line += frame->linesize[0];
+ }
+ return 0;
+}
+
+static inline int write_frame_16(AVPacket *avpkt, AVFrame *frame, PGXContext * const s)
+{
+ int i, j;
+ for (i = 0; i < s->height; i++) {
+ uint16_t *line = (uint16_t*)frame->data[0] + i*frame->linesize[0]/2;
+ for (j = 0; j < s->width; j++) {
+ int val;
+ if (bytestream2_get_bytes_left(&s->g) < 2)
+ return AVERROR_INVALIDDATA;
+ if (s->sign) {
+ val = (int16_t)bytestream2_get_be16(&s->g) + (1 << (s->depth - 1));
+ val <<= (16 - s->depth);
+ *(line + j) = val;
+ } else {
+ val = bytestream2_get_be16u(&s->g);
+ val <<= (16 - s->depth);
+ *(line + j) = val;
+ }
+ }
+ line += frame->linesize[0]/2;
+ }
+ return 0;
+}
+
+static int pgx_decode_frame(AVCodecContext *avctx, void *data,
+ int *got_frame, AVPacket *avpkt)
+{
+ PGXContext *s = avctx->priv_data;
+ AVFrame *p = data;
+ int ret;
+ int bpp;
+ bytestream2_init(&s->g, avpkt->data, avpkt->size);
+ if ((ret = ff_pgx_decode_header(avctx, s)) < 0)
+ return ret;
+
+ if (ret = ff_set_dimensions(avctx, s->width, s->height) < 0)
+ return ret;
+
+ if (s->depth <= 8) {
+ avctx->pix_fmt = AV_PIX_FMT_GRAY8;
+ bpp = 8;
+ } else if (s->depth <= 16) {
+ avctx->pix_fmt = AV_PIX_FMT_GRAY16BE;
+ bpp = 16;
+ } else {
+ av_log(avctx, AV_LOG_ERROR, "Maximum depth of 16 bits supported.\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
+ return ret;
+ *got_frame = 1;
+ p->pict_type = AV_PICTURE_TYPE_I;
+ p->key_frame = 1;
+ avctx->bits_per_raw_sample = s->depth;
+ if (bpp == 8)
+ write_frame_8(avpkt, p, s);
+ else if (bpp == 16)
+ write_frame_16(avpkt, p, s);
+ return 0;
+}
+
+AVCodec ff_pgx_decoder = {
+ .name = "pgx",
+ .long_name = NULL_IF_CONFIG_SMALL("PGX (JPEG2000 Test Format)"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_PGX,
+ .priv_data_size = sizeof(PGXContext),
+ .decode = pgx_decode_frame,
+ .capabilities = AV_CODEC_CAP_DR1,
+};
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 03593026b3..482cc6d6ba 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 58
-#define LIBAVCODEC_VERSION_MINOR 93
+#define LIBAVCODEC_VERSION_MINOR 94
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
--
2.17.1
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