Mobotix .mxg demuxer

Patch by Anatoly Nenashev, anatoly d nenashev a ovsoft d ru

Originally committed as revision 25831 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -59,6 +59,7 @@ version <next>:
 - overlay filter added
 - rename aspect filter to setdar, and pixelaspect to setsar
 - IEC 61937 demuxer
+- Mobotix .mxg demuxer
 
 
 version 0.6:

doc/general.texi

@@ -121,6 +121,7 @@ library:
 @item MAXIS XA @tab @tab X
  @tab Used in Sim City 3000; file extension .xa.
 @item MD Studio @tab @tab X
+@item Mobotix .mxg @tab @tab X
 @item Monkey's Audio @tab @tab X
 @item Motion Pixels MVI @tab @tab X
 @item MOV/QuickTime/MP4 @tab X @tab X

libavcodec/avcodec.h

@@ -256,6 +256,7 @@ enum CodecID {
  CODEC_ID_A64_MULTI,
  CODEC_ID_A64_MULTI5,
  CODEC_ID_R10K,
+ CODEC_ID_MXPEG,
 
  /* various PCM "codecs" */
  CODEC_ID_PCM_S16LE= 0x10000,

libavformat/Makefile

@@ -147,6 +147,7 @@ OBJS-$(CONFIG_MTV_DEMUXER) += mtv.o
 OBJS-$(CONFIG_MVI_DEMUXER) += mvi.o
 OBJS-$(CONFIG_MXF_DEMUXER) += mxfdec.o mxf.o
 OBJS-$(CONFIG_MXF_MUXER) += mxfenc.o mxf.o audiointerleave.o
+OBJS-$(CONFIG_MXG_DEMUXER) += mxg.o
 OBJS-$(CONFIG_NC_DEMUXER) += ncdec.o
 OBJS-$(CONFIG_NSV_DEMUXER) += nsvdec.o
 OBJS-$(CONFIG_NULL_MUXER) += nullenc.o

libavformat/allformats.c

@@ -142,6 +142,7 @@ void av_register_all(void)
  REGISTER_DEMUXER (MVI, mvi);
  REGISTER_MUXDEMUX (MXF, mxf);
  REGISTER_MUXER (MXF_D10, mxf_d10);
+ REGISTER_DEMUXER (MXG, mxg);
  REGISTER_DEMUXER (NC, nc);
  REGISTER_DEMUXER (NSV, nsv);
  REGISTER_MUXER (NULL, null);

libavformat/avformat.h

@@ -22,8 +22,8 @@
 #define AVFORMAT_AVFORMAT_H
 
 #define LIBAVFORMAT_VERSION_MAJOR 52
-#define LIBAVFORMAT_VERSION_MINOR 86
-#define LIBAVFORMAT_VERSION_MICRO 1
+#define LIBAVFORMAT_VERSION_MINOR 87
+#define LIBAVFORMAT_VERSION_MICRO 0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
  LIBAVFORMAT_VERSION_MINOR, \

libavformat/mxg.c

@@ -0,0 +1,251 @@
+/*
+ * MxPEG clip file demuxer
+ * Copyright (c) 2010 Anatoly Nenashev
+ *
+ * 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 "libavutil/intreadwrite.h"
+#include "libavcodec/mjpeg.h"
+#include "avformat.h"
+#include "avio.h"
+
+#define VIDEO_STREAM_INDEX 0
+#define AUDIO_STREAM_INDEX 1
+#define DEFAULT_PACKET_SIZE 1024
+#define OVERREAD_SIZE 3
+
+typedef struct MXGContext {
+ uint8_t *buffer;
+ uint8_t *buffer_ptr;
+ uint8_t *soi_ptr;
+ unsigned int buffer_size;
+ int64_t dts;
+ unsigned int cache_size;
+} MXGContext;
+
+static int mxg_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+ AVStream *video_st, *audio_st;
+ MXGContext *mxg = s->priv_data;
+
+ /* video parameters will be extracted from the compressed bitstream */
+ video_st = av_new_stream(s, VIDEO_STREAM_INDEX);
+ if (!video_st)
+ return AVERROR(ENOMEM);
+ video_st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+ video_st->codec->codec_id = CODEC_ID_MXPEG;
+ av_set_pts_info(video_st, 64, 1, 1000000);
+
+ audio_st = av_new_stream(s, AUDIO_STREAM_INDEX);
+ if (!audio_st)
+ return AVERROR(ENOMEM);
+ audio_st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+ audio_st->codec->codec_id = CODEC_ID_PCM_ALAW;
+ audio_st->codec->channels = 1;
+ audio_st->codec->sample_rate = 8000;
+ audio_st->codec->bits_per_coded_sample = 8;
+ audio_st->codec->block_align = 1;
+ av_set_pts_info(audio_st, 64, 1, 1000000);
+
+ mxg->soi_ptr = mxg->buffer_ptr = mxg->buffer = 0;
+ mxg->buffer_size = 0;
+ mxg->dts = AV_NOPTS_VALUE;
+ mxg->cache_size = 0;
+
+ return 0;
+}
+
+static uint8_t* mxg_find_startmarker(uint8_t *p, uint8_t *end)
+{
+ for (; p < end - 3; p += 4) {
+ uint32_t x = *(uint32_t*)p;
+
+ if (x & (~(x+0x01010101)) & 0x80808080) {
+ if (p[0] == 0xff) {
+ return p;
+ } else if (p[1] == 0xff) {
+ return p+1;
+ } else if (p[2] == 0xff) {
+ return p+2;
+ } else if (p[3] == 0xff) {
+ return p+3;
+ }
+ }
+ }
+
+ for (; p < end; ++p) {
+ if (*p == 0xff) return p;
+ }
+
+ return end;
+}
+
+static int mxg_update_cache(AVFormatContext *s, unsigned int cache_size)
+{
+ MXGContext *mxg = s->priv_data;
+ unsigned int current_pos = mxg->buffer_ptr - mxg->buffer;
+ unsigned int soi_pos;
+ int ret;
+
+ /* reallocate internal buffer */
+ if (current_pos > current_pos + cache_size)
+ return AVERROR(ENOMEM);
+ if (mxg->soi_ptr) soi_pos = mxg->soi_ptr - mxg->buffer;
+ mxg->buffer = av_fast_realloc(mxg->buffer, &mxg->buffer_size,
+ current_pos + cache_size +
+ FF_INPUT_BUFFER_PADDING_SIZE);
+ if (!mxg->buffer)
+ return AVERROR(ENOMEM);
+ mxg->buffer_ptr = mxg->buffer + current_pos;
+ if (mxg->soi_ptr) mxg->soi_ptr = mxg->buffer + soi_pos;
+
+ /* get data */
+ ret = get_buffer(s->pb, mxg->buffer_ptr + mxg->cache_size,
+ cache_size - mxg->cache_size);
+ if (ret < 0)
+ return ret;
+
+ mxg->cache_size += ret;
+
+ return ret;
+}
+
+static int mxg_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ int ret;
+ unsigned int size;
+ uint8_t *startmarker_ptr, *end, *search_end, marker;
+ MXGContext *mxg = s->priv_data;
+
+ while (!url_feof(s->pb) && !url_ferror(s->pb)){
+ if (mxg->cache_size <= OVERREAD_SIZE) {
+ /* update internal buffer */
+ ret = mxg_update_cache(s, DEFAULT_PACKET_SIZE + OVERREAD_SIZE);
+ if (ret < 0)
+ return ret;
+ }
+ end = mxg->buffer_ptr + mxg->cache_size;
+
+ /* find start marker - 0xff */
+ if (mxg->cache_size > OVERREAD_SIZE) {
+ search_end = end - OVERREAD_SIZE;
+ startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end);
+ } else {
+ search_end = end;
+ startmarker_ptr = mxg_find_startmarker(mxg->buffer_ptr, search_end);
+ if (startmarker_ptr >= search_end - 1 ||
+ *(startmarker_ptr + 1) != EOI) break;
+ }
+
+ if (startmarker_ptr != search_end) { /* start marker found */
+ marker = *(startmarker_ptr + 1);
+ mxg->buffer_ptr = startmarker_ptr + 2;
+ mxg->cache_size = end - mxg->buffer_ptr;
+
+ if (marker == SOI) {
+ mxg->soi_ptr = startmarker_ptr;
+ } else if (marker == EOI) {
+ if (!mxg->soi_ptr) {
+ av_log(s, AV_LOG_WARNING, "Found EOI before SOI, skipping\n");
+ continue;
+ }
+
+ pkt->pts = pkt->dts = mxg->dts;
+ pkt->stream_index = VIDEO_STREAM_INDEX;
+ pkt->destruct = NULL;
+ pkt->size = mxg->buffer_ptr - mxg->soi_ptr;
+ pkt->data = mxg->soi_ptr;
+
+ if (mxg->soi_ptr - mxg->buffer > mxg->cache_size) {
+ if (mxg->cache_size > 0) {
+ memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size);
+ }
+
+ mxg->buffer_ptr = mxg->buffer;
+ }
+ mxg->soi_ptr = 0;
+
+ return pkt->size;
+ } else if ( (SOF0 <= marker && marker <= SOF15) ||
+ (SOS <= marker && marker <= COM) ) {
+ /* all other markers that start marker segment also contain
+ length value (see specification for JPEG Annex B.1) */
+ size = AV_RB16(mxg->buffer_ptr);
+ if (size < 2)
+ return AVERROR(EINVAL);
+
+ if (mxg->cache_size < size) {
+ ret = mxg_update_cache(s, size);
+ if (ret < 0)
+ return ret;
+ startmarker_ptr = mxg->buffer_ptr - 2;
+ mxg->cache_size = 0;
+ } else {
+ mxg->cache_size -= size;
+ }
+
+ mxg->buffer_ptr += size;
+
+ if (marker == APP13 && size >= 16) { /* audio data */
+ /* time (GMT) of first sample in usec since 1970, little-endian */
+ pkt->pts = pkt->dts = AV_RL64(startmarker_ptr + 8);
+ pkt->stream_index = AUDIO_STREAM_INDEX;
+ pkt->destruct = NULL;
+ pkt->size = size - 14;
+ pkt->data = startmarker_ptr + 16;
+
+ if (startmarker_ptr - mxg->buffer > mxg->cache_size) {
+ if (mxg->cache_size > 0) {
+ memcpy(mxg->buffer, mxg->buffer_ptr, mxg->cache_size);
+ }
+ mxg->buffer_ptr = mxg->buffer;
+ }
+
+ return pkt->size;
+ } else if (marker == COM && size >= 18 &&
+ !strncmp(startmarker_ptr + 4, "MXF", 3)) {
+ /* time (GMT) of video frame in usec since 1970, little-endian */
+ mxg->dts = AV_RL64(startmarker_ptr + 12);
+ }
+ }
+ } else {
+ /* start marker not found */
+ mxg->buffer_ptr = search_end;
+ mxg->cache_size = OVERREAD_SIZE;
+ }
+ }
+
+ return AVERROR_EOF;
+}
+
+static int mxg_close(struct AVFormatContext *s)
+{
+ MXGContext *mxg = s->priv_data;
+ av_freep(&mxg->buffer);
+ return 0;
+}
+
+AVInputFormat mxg_demuxer = {
+ .name = "mxg",
+ .long_name = NULL_IF_CONFIG_SMALL("MxPEG clip file format"),
+ .priv_data_size = sizeof(MXGContext),
+ .read_header = mxg_read_header,
+ .read_packet = mxg_read_packet,
+ .read_close = mxg_close,
+ .extensions = "mxg"
+};