avcodec: add Radiance HDR image format support

1 files changed, 222 insertions, 0 deletions

diff --git a/libavcodec/hdrdec.c b/libavcodec/hdrdec.c
new file mode 100644
index 0000000000..458215c6ac
--- /dev/null
+++ b/libavcodec/hdrdec.c
@@ -0,0 +1,222 @@
+/*
+ * Radiance HDR image format
+ *
+ * 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 <stdlib.h>
+
+#include "libavutil/imgutils.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "bytestream.h"
+#include "codec_internal.h"
+#include "thread.h"
+
+#define MINELEN 8
+#define MAXELEN 0x7fff
+
+static int hdr_get_line(GetByteContext *gb, uint8_t *buffer, int size)
+{
+    int n = 0, c;
+
+    memset(buffer, 0, size);
+
+    do {
+        c = bytestream2_get_byte(gb);
+        if (n < size - 1)
+            buffer[n++] = c;
+    } while (bytestream2_get_bytes_left(gb) > 0 && c != '\n');
+
+    return 0;
+}
+
+static float convert(int expo, int val)
+{
+    if (expo == -128) {
+        return 0.f;
+    } else {
+        const float v = val / 256.f;
+
+        return ldexpf(v, expo);
+    }
+}
+
+static int decompress(uint8_t *scanline, int w, GetByteContext *gb, const uint8_t *start)
+{
+    int rshift = 0;
+
+    while (w > 0) {
+        scanline[0] = bytestream2_get_byte(gb);
+        scanline[1] = bytestream2_get_byte(gb);
+        scanline[2] = bytestream2_get_byte(gb);
+        scanline[3] = bytestream2_get_byte(gb);
+
+        if (scanline[0] == 1 &&
+            scanline[1] == 1 &&
+            scanline[2] == 1) {
+            int run = scanline[3];
+            for (int i = run << rshift; i > 0 && w > 0 && scanline >= start + 4; i--) {
+                memcpy(scanline, scanline - 4, 4);
+                scanline += 4;
+            }
+            w -= run << rshift;
+            rshift += 8;
+            if (rshift > 16)
+                break;
+        } else {
+            scanline += 4;
+            w--;
+            rshift = 0;
+        }
+    }
+
+    return 1;
+}
+
+static int hdr_decode_frame(AVCodecContext *avctx, AVFrame *p,
+                            int *got_frame, AVPacket *avpkt)
+{
+    const uint8_t *buf = avpkt->data;
+    int ret, buf_size = avpkt->size;
+    int width = 0, height = 0;
+    GetByteContext gb;
+    uint8_t line[512];
+    float sar;
+
+    bytestream2_init(&gb, buf, buf_size);
+    hdr_get_line(&gb, line, sizeof(line));
+    if (memcmp("#?RADIANCE\n", line, 11))
+        return AVERROR_INVALIDDATA;
+
+    do {
+        hdr_get_line(&gb, line, sizeof(line));
+        if (sscanf(line, "PIXASPECT=%f\n", &sar) == 1)
+            avctx->sample_aspect_ratio = p->sample_aspect_ratio = av_inv_q(av_d2q(sar, 4096));
+    } while (line[0] != '\n');
+
+    hdr_get_line(&gb, line, sizeof(line));
+    if (sscanf(line, "-Y %d +X %d\n", &height, &width) == 2) {
+        ;
+    } else if (sscanf(line, "+Y %d +X %d\n", &height, &width) == 2) {
+        ;
+    } else if (sscanf(line, "-Y %d -X %d\n", &height, &width) == 2) {
+        ;
+    } else if (sscanf(line, "+Y %d -X %d\n", &height, &width) == 2) {
+        ;
+    } else if (sscanf(line, "-X %d +Y %d\n", &width, &height) == 2) {
+        ;
+    } else if (sscanf(line, "+X %d +Y %d\n", &width, &height) == 2) {
+        ;
+    } else if (sscanf(line, "-X %d -Y %d\n", &width, &height) == 2) {
+        ;
+    } else if (sscanf(line, "+X %d -Y %d\n", &width, &height) == 2) {
+        ;
+    }
+
+    if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
+        return ret;
+
+    avctx->pix_fmt = AV_PIX_FMT_GBRPF32;
+    if ((ret = ff_thread_get_buffer(avctx, p, 0)) < 0)
+        return ret;
+
+    for (int y = 0; y < height; y++) {
+        float *dst_r = (float *)(p->data[2] + y * p->linesize[2]);
+        float *dst_g = (float *)(p->data[0] + y * p->linesize[0]);
+        float *dst_b = (float *)(p->data[1] + y * p->linesize[1]);
+        uint8_t *scanline = p->data[0] + y * p->linesize[0];
+        int i;
+
+        if (width < MINELEN || width > MAXELEN) {
+            decompress(scanline, width, &gb, scanline);
+            goto convert;
+        }
+
+        i = bytestream2_peek_byte(&gb);
+        if (i != 2) {
+            decompress(scanline, width, &gb, scanline);
+            goto convert;
+        }
+        bytestream2_skip(&gb, 1);
+
+        scanline[1] = bytestream2_get_byte(&gb);
+        scanline[2] = bytestream2_get_byte(&gb);
+        i = bytestream2_get_byte(&gb);
+
+        if (scanline[1] != 2 || scanline[2] & 128) {
+            scanline[0] = 2;
+            scanline[3] = i;
+            decompress(scanline + 4, width - 1, &gb, scanline);
+            goto convert;
+        }
+
+        for (int i = 0; i < 4; i++) {
+            uint8_t *scanline = p->data[0] + y * p->linesize[0] + i;
+
+            for (int j = 0; j < width * 4 && bytestream2_get_bytes_left(&gb) > 0;) {
+                int run = bytestream2_get_byte(&gb);
+                if (run > 128) {
+                    uint8_t val = bytestream2_get_byte(&gb);
+                    run &= 127;
+                    while (run--) {
+                        if (j >= width * 4)
+                            break;
+                        scanline[j] = val;
+                        j += 4;
+                    }
+                } else if (run > 0) {
+                    while (run--) {
+                        if (j >= width * 4)
+                            break;
+                        scanline[j] = bytestream2_get_byte(&gb);
+                        j += 4;
+                    }
+                }
+            }
+        }
+
+convert:
+        for (int x = 0; x < width; x++) {
+            uint8_t rgbe[4];
+            int expo;
+
+            memcpy(rgbe, p->data[0] + y * p->linesize[0] + x * 4, 4);
+            expo = rgbe[3] - 128;
+
+            dst_r[x] = convert(expo, rgbe[0]);
+            dst_b[x] = convert(expo, rgbe[2]);
+            dst_g[x] = convert(expo, rgbe[1]);
+        }
+    }
+
+    p->key_frame = 1;
+    p->pict_type = AV_PICTURE_TYPE_I;
+
+    *got_frame   = 1;
+
+    return buf_size;
+}
+
+const FFCodec ff_hdr_decoder = {
+    .p.name         = "hdr",
+    .p.long_name    = NULL_IF_CONFIG_SMALL("HDR (Radiance RGBE format) image"),
+    .p.type         = AVMEDIA_TYPE_VIDEO,
+    .p.id           = AV_CODEC_ID_RADIANCE_HDR,
+    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
+    FF_CODEC_DECODE_CB(hdr_decode_frame),
+};