From ba83c4bfb55d5c3fc6b3959edb0d3cda07a70241 Mon Sep 17 00:00:00 2001
From: Nicolas George <nicolas.george@normalesup.org>
Date: Thu, 11 Nov 2010 15:24:11 +0000
Subject: MJPEG/AVI1 to JPEG/JFIF bitstream filter.

Originally committed as revision 25721 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/mjpeg2jpeg_bsf.c | 113 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 libavcodec/mjpeg2jpeg_bsf.c

(limited to 'libavcodec/mjpeg2jpeg_bsf.c')

diff --git a/libavcodec/mjpeg2jpeg_bsf.c b/libavcodec/mjpeg2jpeg_bsf.c
new file mode 100644
index 0000000000..36bb749c5a
--- /dev/null
+++ b/libavcodec/mjpeg2jpeg_bsf.c
@@ -0,0 +1,113 @@
+/*
+ * MJPEG/AVI1 to JPEG/JFIF bitstream format filter
+ * Copyright (c) 2010 Adrian Daerr and Nicolas George
+ *
+ * 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
+ */
+
+/*
+ * Adapted from mjpeg2jpeg.c, with original copyright:
+ * Paris 2010 Adrian Daerr, public domain
+ */
+
+#include <string.h>
+#include "avcodec.h"
+#include "mjpeg.h"
+
+static const uint8_t jpeg_header[] = {
+    0xff, 0xd8,                     // SOI
+    0xff, 0xe0,                     // APP0
+    0x00, 0x10,                     // APP0 header size (including
+                                    // this field, but excluding preceding)
+    0x4a, 0x46, 0x49, 0x46, 0x00,   // ID string 'JFIF\0'
+    0x01, 0x01,                     // version
+    0x00,                           // bits per type
+    0x00, 0x00,                     // X density
+    0x00, 0x00,                     // Y density
+    0x00,                           // X thumbnail size
+    0x00,                           // Y thumbnail size
+};
+
+static const int dht_segment_size = 420;
+static const uint8_t dht_segment_head[] = { 0xFF, 0xC4, 0x01, 0xA2, 0x00 };
+static const uint8_t dht_segment_frag[] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+    0x0a, 0x0b, 0x01, 0x00, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
+    0x01, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+
+static uint8_t *append(uint8_t *buf, const uint8_t *src, int size)
+{
+    memcpy(buf, src, size);
+    return buf + size;
+}
+
+static uint8_t *append_dht_segment(uint8_t *buf)
+{
+    buf = append(buf, dht_segment_head, sizeof(dht_segment_head));
+    buf = append(buf, ff_mjpeg_bits_dc_luminance + 1, 16);
+    buf = append(buf, dht_segment_frag, sizeof(dht_segment_frag));
+    buf = append(buf, ff_mjpeg_val_dc, 12);
+    *(buf++) = 0x10;
+    buf = append(buf, ff_mjpeg_bits_ac_luminance + 1, 16);
+    buf = append(buf, ff_mjpeg_val_ac_luminance, 162);
+    *(buf++) = 0x11;
+    buf = append(buf, ff_mjpeg_bits_ac_chrominance + 1, 16);
+    buf = append(buf, ff_mjpeg_val_ac_chrominance, 162);
+    return buf;
+}
+
+static int mjpeg2jpeg_filter(AVBitStreamFilterContext *bsfc,
+                             AVCodecContext *avctx, const char *args,
+                             uint8_t **poutbuf, int *poutbuf_size,
+                             const uint8_t *buf, int buf_size,
+                             int keyframe)
+{
+    int input_skip, output_size;
+    uint8_t *output, *out;
+
+    if (buf_size < 12) {
+        av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
+        return AVERROR_INVALIDDATA;
+    }
+    if (memcmp("AVI1", buf + 6, 4)) {
+        av_log(avctx, AV_LOG_ERROR, "input is not MJPEG/AVI1\n");
+        return AVERROR_INVALIDDATA;
+    }
+    input_skip = (buf[4] << 8) + buf[5] + 4;
+    if (buf_size < input_skip) {
+        av_log(avctx, AV_LOG_ERROR, "input is truncated\n");
+        return AVERROR_INVALIDDATA;
+    }
+    output_size = buf_size - input_skip +
+                  sizeof(jpeg_header) + dht_segment_size;
+    output = out = av_malloc(output_size);
+    if (!output)
+        return AVERROR(ENOMEM);
+    out = append(out, jpeg_header, sizeof(jpeg_header));
+    out = append_dht_segment(out);
+    out = append(out, buf + input_skip, buf_size - input_skip);
+    *poutbuf = output;
+    *poutbuf_size = output_size;
+    return 1;
+}
+
+AVBitStreamFilter mjpeg2jpeg_bsf = {
+    .name           = "mjpeg2jpeg",
+    .priv_data_size = 0,
+    .filter         = mjpeg2jpeg_filter,
+};
-- 
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