[Ffmpeg-devel] [PATCH] THP Demuxer (Summer of Code qualification task)
Marco Gerards
mgerards
Fri Mar 30 01:45:11 CEST 2007
Michael Niedermayer <michaelni at gmx.at> writes:
Hi,
>> Here is a patch (sent inline) to add a THP demuxer to ffmpeg. I've
>> also changed the MPJEG decoder so it can play THP movies. This is a
>> qualification task for Google Summer of Code 2007.
>>
>> It perfectly plays back the samples that can be found on the ffmpeg
>> website. Unfortunately these samples come without audio. Because of
>> this I haven't implemented audio support yet. I hope someone can send
>> me a sample that includes audio. In that case I will implement this
>> as well.
>>
>> If I can do something to improve my code or to add something that is
>> missing, please tell me.
[...]
> tabs are forbidden in svn
> additionally cosmetic changes and functional changes must be in seperate
> patches, that is dont change whitespace or indention just add the
> if (avctx->codec_id != CODEC_ID_THP){ ... } in the first patch
> and fix the indention (and only the indention) in a second patch
> this makes reviewing patches (and commits on svnlog) much easier
Ok. I have fixed this.
>
> [...]
>> Index: libavcodec/avcodec.h
>> ===================================================================
>> --- libavcodec/avcodec.h (revision 8540)
>> +++ libavcodec/avcodec.h (working copy)
>> @@ -64,6 +64,7 @@
>> CODEC_ID_RV20,
>> CODEC_ID_MJPEG,
>> CODEC_ID_MJPEGB,
>> + CODEC_ID_THP,
>> CODEC_ID_LJPEG,
>
> read the comment at the top of this CODEC_ID list!
> you cannot add new codec_ids at random places this breaks the ABI
Fixed. I have added the codec id to the end of the list.
> [...]
>> + for (i = 0; i < thp->compcount; i++) {
>> + if (thp->components[i] == 0) {
>
>> + if (thp->vst != 0)
>> + break;
>
> why do you discard a second video stream?
Because the documentation doesn't mention this possibility. And I
doubt it will be used in reality. Do you think this is important and
are there samples which I can use to test this?
[...]
I also fixed all other things you commented on, see the new patch
below. The most mistakes I made were because I copied a lot from
other demuxers. Is there any good documentation available about how
to do all this correctly instead of looking at other demuxers?
--
Marco
Index: libavcodec/mjpeg.c
===================================================================
--- libavcodec/mjpeg.c (revision 8550)
+++ libavcodec/mjpeg.c (working copy)
@@ -2044,6 +2044,9 @@
uint8_t x = *(src++);
*(dst++) = x;
+ if (avctx->codec_id != CODEC_ID_THP)
+ {
+
if (x == 0xff)
{
while(src<buf_end && x == 0xff)
@@ -2054,6 +2057,7 @@
else if (x)
break;
}
+ }
}
init_get_bits(&s->gb, s->buffer, (dst - s->buffer)*8);
@@ -2583,6 +2587,19 @@
NULL
};
+AVCodec thp_decoder = {
+ "thp",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_THP,
+ sizeof(MJpegDecodeContext),
+ mjpeg_decode_init,
+ NULL,
+ mjpeg_decode_end,
+ mjpeg_decode_frame,
+ CODEC_CAP_DR1,
+ NULL
+};
+
AVCodec mjpegb_decoder = {
"mjpegb",
CODEC_TYPE_VIDEO,
Index: libavcodec/allcodecs.c
===================================================================
--- libavcodec/allcodecs.c (revision 8540)
+++ libavcodec/allcodecs.c (working copy)
@@ -130,6 +130,7 @@
REGISTER_DECODER(SVQ3, svq3);
REGISTER_ENCDEC (TARGA, targa);
REGISTER_DECODER(THEORA, theora);
+ REGISTER_DECODER(THP, thp);
REGISTER_DECODER(TIERTEXSEQVIDEO, tiertexseqvideo);
REGISTER_DECODER(TIFF, tiff);
REGISTER_DECODER(TRUEMOTION1, truemotion1);
Index: libavcodec/avcodec.h
===================================================================
--- libavcodec/avcodec.h (revision 8540)
+++ libavcodec/avcodec.h (working copy)
@@ -255,6 +255,8 @@
CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport
stream (only used by libavformat) */
+
+ CODEC_ID_THP
};
#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
@@ -2329,6 +2331,7 @@
extern AVCodec svq3_decoder;
extern AVCodec targa_decoder;
extern AVCodec theora_decoder;
+extern AVCodec thp_decoder;
extern AVCodec tiertexseqvideo_decoder;
extern AVCodec tiff_decoder;
extern AVCodec truemotion1_decoder;
Index: libavformat/thp.c
===================================================================
--- libavformat/thp.c (revision 0)
+++ libavformat/thp.c (revision 0)
@@ -0,0 +1,165 @@
+/*
+ * THP Demuxer
+ * Copyright (c) 2007 Marco Gerards.
+ *
+ * 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 "avformat.h"
+#include "allformats.h"
+
+typedef struct ThpDemuxContext {
+ int version;
+ int first_frame;
+ int first_framesz;
+ int last_frame;
+ int compoff;
+ int framecnt;
+ AVRational fps;
+ int frame;
+ int next_frame;
+ int next_framesz;
+ int video_stream_index;
+ int compcount;
+ unsigned char components[16];
+ AVStream* vst;
+} ThpDemuxContext;
+
+
+static int thp_probe(AVProbeData *p)
+{
+ /* check file header */
+ if (p->buf_size < 4)
+ return 0;
+
+ if (AV_RL32(p->buf) == MKTAG('T', 'H', 'P', '\0'))
+ return AVPROBE_SCORE_MAX;
+ else
+ return 0;
+}
+
+static int thp_read_header(AVFormatContext *s,
+ AVFormatParameters *ap)
+{
+ ThpDemuxContext *thp = s->priv_data;
+ AVStream *st;
+ ByteIOContext *pb = &s->pb;
+ int i;
+
+ /* Read the file header. */
+
+ get_be32(pb); /* Skip Magic. */
+ thp->version = get_be32(pb);
+
+ get_be32(pb); /* Max buf size. */
+ get_be32(pb); /* Max samples. */
+
+ thp->fps = av_d2q(av_int2flt(get_be32(pb)), INT_MAX);
+ thp->framecnt = get_be32(pb);
+ thp->first_framesz = get_be32(pb);
+ get_be32(pb); /* Data size. */
+
+ thp->compoff = get_be32(pb);
+ get_be32(pb); /* offsetDataOffset. */
+ thp->first_frame = get_be32(pb);
+ thp->last_frame = get_be32(pb);
+
+ thp->next_framesz = thp->first_framesz;
+ thp->next_frame = thp->first_frame;
+
+ /* Read the component structure. */
+ url_fseek (pb, thp->compoff, SEEK_SET);
+ thp->compcount = get_be32(pb);
+
+ /* Read the list of component types. */
+ get_buffer(pb, thp->components, 16);
+
+ for (i = 0; i < thp->compcount; i++) {
+ if (thp->components[i] == 0) {
+ if (thp->vst != 0)
+ break;
+
+ /* Video component. */
+ st = av_new_stream(s, 0);
+ if (!st)
+ return AVERROR_NOMEM;
+
+ /* The denominator and numerator are switched because 1/fps
+ is required. */
+ av_set_pts_info(st, 64, thp->fps.den, thp->fps.num);
+ st->codec->codec_type = CODEC_TYPE_VIDEO;
+ st->codec->codec_id = CODEC_ID_THP;
+ st->codec->codec_tag = 0; /* no fourcc */
+ st->codec->width = get_be32(pb);
+ st->codec->height = get_be32(pb);
+ st->codec->sample_rate = av_q2d(thp->fps);
+ thp->vst = st;
+ thp->video_stream_index = st->index;
+
+ if (thp->version == 0x11000)
+ get_be32(pb); /* Unknown. */
+ }
+ else if (thp->components[i] == 1) {
+ /* XXX: Required for audio playback. */
+ }
+ }
+
+ return 0;
+}
+
+static int thp_read_packet(AVFormatContext *s,
+ AVPacket *pkt)
+{
+ ThpDemuxContext *thp = s->priv_data;
+ ByteIOContext *pb = &s->pb;
+ int size;
+ int ret;
+
+ /* Terminate when last frame is reached. */
+ if (thp->frame >= thp->framecnt)
+ return AVERROR_IO;
+
+ url_fseek(pb, thp->next_frame, SEEK_SET);
+
+ /* Locate the next frame and read out its size. */
+ thp->next_frame += thp->next_framesz;
+ thp->next_framesz = get_be32(pb);
+
+ get_be32(pb); /* Previous total size. */
+ size = get_be32(pb); /* Total size of this frame. */
+
+ ret = av_get_packet(pb, pkt, size);
+ if (ret != size) {
+ av_free_packet(pkt);
+ return AVERROR_IO;
+ }
+
+ pkt->stream_index = thp->video_stream_index;
+ thp->frame++;
+
+ return 0;
+}
+
+AVInputFormat thp_demuxer = {
+ "tph",
+ "TPH",
+ sizeof(ThpDemuxContext),
+ thp_probe,
+ thp_read_header,
+ thp_read_packet
+};
Index: libavformat/Makefile
===================================================================
--- libavformat/Makefile (revision 8540)
+++ libavformat/Makefile (working copy)
@@ -120,6 +120,7 @@
OBJS-$(CONFIG_SOL_DEMUXER) += sol.o
OBJS-$(CONFIG_SWF_DEMUXER) += swf.o
OBJS-$(CONFIG_SWF_MUXER) += swf.o
+OBJS-$(CONFIG_THP_DEMUXER) += thp.o
OBJS-$(CONFIG_TIERTEXSEQ_DEMUXER) += tiertexseq.o
OBJS-$(CONFIG_TTA_DEMUXER) += tta.o
OBJS-$(CONFIG_V4L2_DEMUXER) += v4l2.o
Index: libavformat/allformats.c
===================================================================
--- libavformat/allformats.c (revision 8540)
+++ libavformat/allformats.c (working copy)
@@ -142,6 +142,7 @@
REGISTER_MUXDEMUX(SWF, swf);
REGISTER_MUXER (TG2, tg2);
REGISTER_MUXER (TGP, tgp);
+ REGISTER_DEMUXER (THP, thp);
REGISTER_DEMUXER (TIERTEXSEQ, tiertexseq);
REGISTER_DEMUXER (TTA, tta);
REGISTER_DEMUXER (V4L2, v4l2);
Index: libavformat/allformats.h
===================================================================
--- libavformat/allformats.h (revision 8540)
+++ libavformat/allformats.h (working copy)
@@ -168,6 +168,7 @@
extern AVInputFormat yuv4mpegpipe_demuxer;
extern AVInputFormat tiertexseq_demuxer;
extern AVInputFormat x11_grab_device_demuxer;
+extern AVInputFormat thp_demuxer;
/* raw.c */
int pcm_read_seek(AVFormatContext *s,
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