@@ -53,6 +53,7 @@ version <next>:

 - single stream LATM/LOAS decoder

 - setpts filter added

 - Win64 support for optimized asm functions

+- MJPEG/AVI1 to JPEG/JFIF bitstream filter

 version 0.6:

@@ -25,6 +25,43 @@ Below is a description of the currently available bitstream filters.

 @section imx_dump_header

+@section mjpeg2jpeg

+

+Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.

+

+MJPEG is a video codec wherein each video frame is essentially a

+JPEG image. The individual frames can be extracted without loss,

+e.g. by

+

+@example

+ffmpeg -i ../some_mjpeg.avi -vcodec copy frames_%d.jpg

+@end example

+

+Unfortunately, these chunks are incomplete JPEG images, because

+they lack the DHT segment required for decoding. Quoting from

+@url{http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml}:

+

+Avery Lee, writing in the rec.video.desktop newsgroup in 2001,

+commented that "MJPEG, or at least the MJPEG in AVIs having the

+MJPG fourcc, is restricted JPEG with a fixed -- and *omitted* --

+Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,

+and it must use basic Huffman encoding, not arithmetic or

+progressive. . . . You can indeed extract the MJPEG frames and

+decode them with a regular JPEG decoder, but you have to prepend

+the DHT segment to them, or else the decoder won't have any idea

+how to decompress the data. The exact table necessary is given in

+the OpenDML spec."

+

+This bitstream filter patches the header of frames extracted from an MJPEG

+stream (carrying the AVI1 header ID and lacking a DHT segment) to

+produce fully qualified JPEG images.

+

+@example

+ffmpeg -i mjpeg-movie.avi -vcodec copy -vbsf mjpeg2jpeg frame_%d.jpg

+exiftran -i -9 frame*.jpg

+ffmpeg -i frame_%d.jpg -vcodec copy rotated.avi

+@end example

+

 @section mjpega_dump_header

 @section movsub

@@ -522,7 +522,7 @@ Force video tag/fourcc.

 @item -qphist

 Show QP histogram.

 @item -vbsf @var{bitstream_filter}

-Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump".

+Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump", "mjpeg2jpeg".

 @example

 ffmpeg -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264

 @end example

@@ -602,6 +602,7 @@ OBJS-$(CONFIG_CHOMP_BSF)                  += chomp_bsf.o

 OBJS-$(CONFIG_DUMP_EXTRADATA_BSF)         += dump_extradata_bsf.o

 OBJS-$(CONFIG_H264_MP4TOANNEXB_BSF)       += h264_mp4toannexb_bsf.o

 OBJS-$(CONFIG_IMX_DUMP_HEADER_BSF)        += imx_dump_header_bsf.o

+OBJS-$(CONFIG_MJPEG2JPEG_BSF)             += mjpeg2jpeg_bsf.o

 OBJS-$(CONFIG_MJPEGA_DUMP_HEADER_BSF)     += mjpega_dump_header_bsf.o

 OBJS-$(CONFIG_MOV2TEXTSUB_BSF)            += movsub_bsf.o

 OBJS-$(CONFIG_MP3_HEADER_COMPRESS_BSF)    += mp3_header_compress_bsf.o

@@ -394,6 +394,7 @@ void avcodec_register_all(void)

     REGISTER_BSF     (DUMP_EXTRADATA, dump_extradata);

     REGISTER_BSF     (H264_MP4TOANNEXB, h264_mp4toannexb);

     REGISTER_BSF     (IMX_DUMP_HEADER, imx_dump_header);

+    REGISTER_BSF     (MJPEG2JPEG, mjpeg2jpeg);

     REGISTER_BSF     (MJPEGA_DUMP_HEADER, mjpega_dump_header);

     REGISTER_BSF     (MP3_HEADER_COMPRESS, mp3_header_compress);

     REGISTER_BSF     (MP3_HEADER_DECOMPRESS, mp3_header_decompress);

new file mode 100644

@@ -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,

+};