diff mbox series

[FFmpeg-devel,RFC,1/2] libavcodec/pgxdec: Add PGX decoder

Message ID 20200626193730.4000-1-gautamramk@gmail.com
State Superseded
Headers show
Series [FFmpeg-devel,RFC,1/2] libavcodec/pgxdec: Add PGX decoder
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Commit Message

Gautam Ramakrishnan June 26, 2020, 7:37 p.m. UTC
From: Gautam Ramakrishnan <gautamramk@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

Comments

Carl Eugen Hoyos June 26, 2020, 8:47 p.m. UTC | #1
> Am 26.06.2020 um 21:37 schrieb gautamramk@gmail.com:
> 
> +        .long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),

This seems wrong as long description for the “pgx (jpeg2000 test format)”.

Carl Eugen
Gautam Ramakrishnan June 26, 2020, 8:50 p.m. UTC | #2
On Sat, Jun 27, 2020 at 2:17 AM Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:
>
>
>
> > Am 26.06.2020 um 21:37 schrieb gautamramk@gmail.com:
> >
> > +        .long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),
>
> This seems wrong as long description for the “pgx (jpeg2000 test format)”.
>
Thanks, I misunderstood the contents of this.
Gautam Ramakrishnan June 26, 2020, 9:19 p.m. UTC | #3
On Sat, Jun 27, 2020 at 2:20 AM Gautam Ramakrishnan
<gautamramk@gmail.com> wrote:
>
> On Sat, Jun 27, 2020 at 2:17 AM Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:
> >
> >
> >
> > > Am 26.06.2020 um 21:37 schrieb gautamramk@gmail.com:
> > >
> > > +        .long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),
> >
> > This seems wrong as long description for the “pgx (jpeg2000 test format)”.
> >
> Thanks, I misunderstood the contents of this.
I changed the .long_name field in both pgxdec.c and codec_desc.c to
"PGX (JPEG2000 Test Format)". However fate throws the following error
avcodec_descriptor_get() failed with 'pgx'.
diff mbox series

Patch

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
+@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..16d995147f 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -3381,6 +3381,13 @@  static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),
         .props     = AV_CODEC_PROP_LOSSLESS,
     },
+    {
+        .id        = AV_CODEC_ID_PGX,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "pgx",
+        .long_name = NULL_IF_CONFIG_SMALL("AVFrame to AVPacket passthrough"),
+        .props     = AV_CODEC_PROP_LOSSLESS,
+    },
 };
 
 static int descriptor_compare(const void *key, const void *member)
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..1be5a91eac
--- /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 image"),
+    .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, \