[FFmpeg-devel] [PATCH] Bitmap Brothers JV demuxer
Peter Ross
pross
Wed Mar 9 11:45:41 CET 2011
---
On Tue, Mar 08, 2011 at 04:35:54PM +0100, Kostya wrote:
> On Wed, Mar 09, 2011 at 02:10:50AM +1100, Peter Ross wrote:
[..]
> > +static int read_probe(AVProbeData *pd)
> > +{
> > + if (pd->buf[0] == 'J' && pd->buf[1] == 'V' &&
> > + !memcmp(pd->buf + 4, MAGIC, FFMIN(strlen(MAGIC), pd->buf_size - 4)))
> > + return AVPROBE_SCORE_MAX;
> > + return 0;
> > +}
>
> I think it's wrong to return score_max if you have too small probe buffer not
> to fit all magic string.
Isn't buf_size guaranteed to be at least 32-bytes? So in the worst case, the
memcmp will compare 28 bytes, which is still a strong enough indicator IMHO.
> [...]
>
> BTW, do you initialise state explicitly somewhere?
JvContext.state defaults to zero when priv_data is allocated. In this updated
patch, i've forced the JV_AUDIO state enum to be zero. That way theres no
need to specifically initialise it in decode_init().
> > + avio_skip(pb, e->size - jvf->audio_size - jvf->video_size - (jvf->palette ? 768 : 0));
>
> Is that guaranteed to be always non-negative?
Noo! Nicely spotted. While all known JV samples have >=0 padding bytes, a fuzzed
file could cause a endless loop here, so its best that to clamp the range.
>
> Nice state machine you have here though.
>
> [the rest rises no comments from me]
Thanks for the prompt review.
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/jvdec.c | 220 ++++++++++++++++++++++++++++++++++++++++++++++
libavformat/version.h | 2 +-
4 files changed, 223 insertions(+), 1 deletions(-)
create mode 100644 libavformat/jvdec.c
diff --git a/libavformat/Makefile b/libavformat/Makefile
index eb9ca49..4eb1620 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -110,6 +110,7 @@ OBJS-$(CONFIG_ISS_DEMUXER) += iss.o
OBJS-$(CONFIG_IV8_DEMUXER) += iv8.o
OBJS-$(CONFIG_IVF_DEMUXER) += ivfdec.o riff.o
OBJS-$(CONFIG_IVF_MUXER) += ivfenc.o
+OBJS-$(CONFIG_JV_DEMUXER) += jvdec.o
OBJS-$(CONFIG_LMLM4_DEMUXER) += lmlm4.o
OBJS-$(CONFIG_LXF_DEMUXER) += lxfdec.o
OBJS-$(CONFIG_M4V_DEMUXER) += m4vdec.o rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 562f624..bca968a 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -110,6 +110,7 @@ void av_register_all(void)
REGISTER_DEMUXER (ISS, iss);
REGISTER_DEMUXER (IV8, iv8);
REGISTER_MUXDEMUX (IVF, ivf);
+ REGISTER_DEMUXER (JV, jv);
REGISTER_DEMUXER (LMLM4, lmlm4);
REGISTER_DEMUXER (LXF, lxf);
REGISTER_MUXDEMUX (M4V, m4v);
diff --git a/libavformat/jvdec.c b/libavformat/jvdec.c
new file mode 100644
index 0000000..d804ed9
--- /dev/null
+++ b/libavformat/jvdec.c
@@ -0,0 +1,220 @@
+/*
+ * Bitmap Brothers JV demuxer
+ * Copyright (c) 2005, 2011 Peter Ross <pross at xvid.org>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Bitmap Brothers JV demuxer
+ * @author Peter Ross <pross at xvid.org>
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+
+typedef struct {
+ int audio_size; /** audio packet size (bytes) */
+ int video_size; /** video packet size (bytes) */
+ int palette; /** frame contains palette change */
+ int video_type; /** per-frame video compression type */
+} JVFrame;
+
+typedef struct {
+ JVFrame *frames;
+ enum {
+ JV_AUDIO = 0,
+ JV_VIDEO,
+ JV_PADDING
+ } state;
+ int64_t pts;
+} JVDemuxContext;
+
+#define MAGIC " Compression by John M Phillips Copyright (C) 1995 The Bitmap Brothers Ltd."
+
+static int read_probe(AVProbeData *pd)
+{
+ if (pd->buf[0] == 'J' && pd->buf[1] == 'V' &&
+ !memcmp(pd->buf + 4, MAGIC, FFMIN(strlen(MAGIC), pd->buf_size - 4)))
+ return AVPROBE_SCORE_MAX;
+ return 0;
+}
+
+static int read_header(AVFormatContext *s,
+ AVFormatParameters *ap)
+{
+ JVDemuxContext *jv = s->priv_data;
+ AVIOContext *pb = s->pb;
+ AVStream *vst, *ast;
+ int64_t audio_pts = 0;
+ int64_t offset;
+ int i;
+
+ avio_skip(pb, 80);
+
+ ast = av_new_stream(s, 0);
+ vst = av_new_stream(s, 1);
+ if (!ast || !vst)
+ return AVERROR(ENOMEM);
+
+ vst->codec->codec_type = CODEC_TYPE_VIDEO;
+ vst->codec->codec_id = CODEC_ID_JV;
+ vst->codec->codec_tag = 0; /* no fourcc */
+ vst->codec->width = avio_rl16(pb);
+ vst->codec->height = avio_rl16(pb);
+ vst->nb_frames =
+ ast->nb_index_entries = avio_rl16(pb);
+ av_set_pts_info(vst, 64, avio_rl16(pb), 1000);
+
+ avio_skip(pb, 4);
+
+ ast->codec->codec_type = CODEC_TYPE_AUDIO;
+ ast->codec->codec_id = CODEC_ID_PCM_U8;
+ ast->codec->codec_tag = 0; /* no fourcc */
+ ast->codec->sample_rate = avio_rl16(pb);
+ ast->codec->channels = 1;
+ av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
+
+ avio_skip(pb, 10);
+
+ ast->index_entries = av_malloc(ast->nb_index_entries * sizeof(*ast->index_entries));
+ if (!ast->index_entries)
+ return AVERROR(ENOMEM);
+
+ jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));
+ if (!jv->frames)
+ return AVERROR(ENOMEM);
+
+ offset = 0x68 + ast->nb_index_entries * 16;
+ for(i = 0; i < ast->nb_index_entries; i++) {
+ AVIndexEntry *e = ast->index_entries + i;
+ JVFrame *jvf = jv->frames + i;
+
+ /* total frame size including audio, video, palette data and padding */
+ e->size = avio_rl32(pb);
+ e->timestamp = i;
+ e->pos = offset;
+ offset += e->size;
+
+ jvf->audio_size = avio_rl32(pb);
+ jvf->video_size = avio_rl32(pb);
+ jvf->palette = avio_r8(pb);
+ if (avio_r8(pb))
+ av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");
+ jvf->video_type = avio_r8(pb);
+ avio_skip(pb, 1);
+
+ e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;
+ audio_pts += jvf->audio_size;
+
+ e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;
+ }
+
+ return 0;
+}
+
+static int read_packet(AVFormatContext *s,
+ AVPacket *pkt)
+{
+ JVDemuxContext *jv = s->priv_data;
+ AVIOContext *pb = s->pb;
+ AVStream *ast = s->streams[0];
+
+ while (!url_feof(s->pb) && jv->pts < ast->nb_index_entries) {
+ const AVIndexEntry *e = ast->index_entries + jv->pts;
+ const JVFrame *jvf = jv->frames + jv->pts;
+
+ switch(jv->state) {
+ case JV_AUDIO:
+ jv->state++;
+ if (jvf->audio_size ) {
+ if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)
+ return AVERROR(ENOMEM);
+ pkt->stream_index = 0;
+ pkt->pts = e->timestamp;
+ pkt->flags |= PKT_FLAG_KEY;
+ return 0;
+ }
+ case JV_VIDEO:
+ jv->state++;
+ if (jvf->video_size || jvf->palette) {
+ int size = jvf->video_size + (jvf->palette ? 768 : 0);
+ if (av_new_packet(pkt, size + 5))
+ return AVERROR(ENOMEM);
+
+ AV_WL32(pkt->data, jvf->video_size);
+ pkt->data[4] = jvf->video_type;
+ if (avio_read(pb, pkt->data + 5, size) < 0)
+ return AVERROR(EIO);
+
+ pkt->size = size + 5;
+ pkt->stream_index = 1;
+ pkt->pts = jv->pts;
+ if (jvf->video_type != 1)
+ pkt->flags |= PKT_FLAG_KEY;
+ return 0;
+ }
+ case JV_PADDING:
+ avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size - (jvf->palette ? 768 : 0), 0));
+ jv->state = JV_AUDIO;
+ jv->pts++;
+ }
+ }
+
+ return AVERROR(EIO);
+}
+
+static int read_seek(AVFormatContext *s, int stream_index,
+ int64_t ts, int flags)
+{
+ JVDemuxContext *jv = s->priv_data;
+ AVStream *ast = s->streams[0];
+ int i;
+
+ if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))
+ return AVERROR_NOTSUPP;
+
+ switch(stream_index) {
+ case 0:
+ i = av_index_search_timestamp(ast, ts, flags);
+ break;
+ case 1:
+ i = ts;
+ break;
+ default:
+ return 0;
+ }
+
+ if (i < 0 || i >= ast->nb_index_entries)
+ return 0;
+
+ jv->state = JV_AUDIO;
+ jv->pts = i;
+ avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET);
+ return 0;
+}
+
+AVInputFormat ff_jv_demuxer = {
+ .name = "jv",
+ .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),
+ .priv_data_size = sizeof(JVDemuxContext),
+ .read_probe = read_probe,
+ .read_header = read_header,
+ .read_packet = read_packet,
+ .read_seek = read_seek,
+};
diff --git a/libavformat/version.h b/libavformat/version.h
index 494cf11..aed8908 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -24,7 +24,7 @@
#include "libavutil/avutil.h"
#define LIBAVFORMAT_VERSION_MAJOR 52
-#define LIBAVFORMAT_VERSION_MINOR 102
+#define LIBAVFORMAT_VERSION_MINOR 103
#define LIBAVFORMAT_VERSION_MICRO 0
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
--
1.7.1
-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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