rl2 demuxer

Originally committed as revision 12545 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 299 insertions, 0 deletions

diff --git a/libavformat/rl2.c b/libavformat/rl2.c
new file mode 100644
index 0000000000..30f065bb81
--- /dev/null
+++ b/libavformat/rl2.c
@@ -0,0 +1,299 @@
+/*
+ * RL2 Format Demuxer
+ * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
+ *
+ * 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
+ */
+
+/**
+ * RL2 file demuxer
+ * @file rl2.c
+ * @author Sascha Sommer (saschasommer@freenet.de)
+ * For more information regarding the RL2 file format, visit:
+ *   http://wiki.multimedia.cx/index.php?title=RL2
+ *
+ * extradata:
+ * 2 byte le initial drawing offset within 320x200 viewport
+ * 4 byte le number of used colors
+ * 256 * 3 bytes rgb palette
+ * optional background_frame
+ */
+
+#include "avformat.h"
+
+#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
+
+#define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
+#define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
+#define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
+
+typedef struct Rl2DemuxContext {
+    unsigned int index_pos[2];   ///< indices in the sample tables
+} Rl2DemuxContext;
+
+
+/**
+ * check if the file is in rl2 format
+ * @param p probe buffer
+ * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
+ */
+static int rl2_probe(AVProbeData *p)
+{
+
+    if(AV_RB32(&p->buf[0]) != FORM_TAG)
+        return 0;
+
+    if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
+        AV_RB32(&p->buf[8]) != RLV3_TAG)
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+/**
+ * read rl2 header data and setup the avstreams
+ * @param s demuxer context
+ * @param ap format parameters
+ * @return 0 on success, AVERROR otherwise
+ */
+static av_cold int rl2_read_header(AVFormatContext *s,
+                            AVFormatParameters *ap)
+{
+    ByteIOContext *pb = s->pb;
+    AVStream *st;
+    unsigned int frame_count;
+    unsigned int audio_frame_counter = 0;
+    unsigned int video_frame_counter = 0;
+    unsigned int back_size;
+    int data_size;
+    unsigned short encoding_method;
+    unsigned short sound_rate;
+    unsigned short rate;
+    unsigned short channels;
+    unsigned short def_sound_size;
+    unsigned int signature;
+    unsigned int pts_den = 11025; /* video only case */
+    unsigned int pts_num = 1103;
+    unsigned int* chunk_offset = NULL;
+    int* chunk_size = NULL;
+    int* audio_size = NULL;
+    int i;
+    int ret = 0;
+
+    url_fskip(pb,4);          /* skip FORM tag */
+    back_size = get_le32(pb); /** get size of the background frame */
+    signature = get_be32(pb);
+    data_size = get_be32(pb);
+    frame_count = get_le32(pb);
+
+    /* disallow back_sizes and frame_counts that may lead to overflows later */
+    if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
+        return AVERROR_INVALIDDATA;
+
+    encoding_method = get_le16(pb);
+    sound_rate = get_le16(pb);
+    rate = get_le16(pb);
+    channels = get_le16(pb);
+    def_sound_size = get_le16(pb);
+
+    /** setup video stream */
+    st = av_new_stream(s, 0);
+    if(!st)
+         return AVERROR(ENOMEM);
+
+    st->codec->codec_type = CODEC_TYPE_VIDEO;
+    st->codec->codec_id = CODEC_ID_RL2;
+    st->codec->codec_tag = 0;  /* no fourcc */
+    st->codec->width = 320;
+    st->codec->height = 200;
+
+    /** allocate and fill extradata */
+    st->codec->extradata_size = EXTRADATA1_SIZE;
+
+    if(signature == RLV3_TAG && back_size > 0)
+        st->codec->extradata_size += back_size;
+
+    st->codec->extradata = av_mallocz(st->codec->extradata_size +
+                                          FF_INPUT_BUFFER_PADDING_SIZE);
+    if(!st->codec->extradata)
+        return AVERROR(ENOMEM);
+
+    if(get_buffer(pb,st->codec->extradata,st->codec->extradata_size) !=
+                      st->codec->extradata_size)
+        return AVERROR(EIO);
+
+    /** setup audio stream if present */
+    if(sound_rate){
+        pts_num = def_sound_size;
+        pts_den = rate;
+
+        st = av_new_stream(s, 0);
+        if (!st)
+            return AVERROR(ENOMEM);
+        st->codec->codec_type = CODEC_TYPE_AUDIO;
+        st->codec->codec_id = CODEC_ID_PCM_U8;
+        st->codec->codec_tag = 1;
+        st->codec->channels = channels;
+        st->codec->bits_per_sample = 8;
+        st->codec->sample_rate = rate;
+        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
+            st->codec->bits_per_sample;
+        st->codec->block_align = st->codec->channels *
+            st->codec->bits_per_sample / 8;
+        av_set_pts_info(st,32,1,rate);
+    }
+
+    av_set_pts_info(s->streams[0], 32, pts_num, pts_den);
+
+    chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
+    audio_size =   av_malloc(frame_count * sizeof(uint32_t));
+    chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
+
+    if(!chunk_size || !audio_size || !chunk_offset){
+        av_free(chunk_size);
+        av_free(audio_size);
+        av_free(chunk_offset);
+        return AVERROR(ENOMEM);
+    }
+
+    /** read offset and size tables */
+    for(i=0; i < frame_count;i++)
+        chunk_size[i] = get_le32(pb);
+    for(i=0; i < frame_count;i++)
+        chunk_offset[i] = get_le32(pb);
+    for(i=0; i < frame_count;i++)
+        audio_size[i] = get_le32(pb) & 0xFFFF;
+
+    /** build the sample index */
+    for(i=0;i<frame_count;i++){
+        if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
+            ret = AVERROR_INVALIDDATA;
+            break;
+        }
+
+        if(sound_rate && audio_size[i]){
+            av_add_index_entry(s->streams[1], chunk_offset[i],
+                audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
+            audio_frame_counter += audio_size[i] / channels;
+        }
+        av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
+            video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
+        ++video_frame_counter;
+    }
+
+
+    av_free(chunk_size);
+    av_free(audio_size);
+    av_free(chunk_offset);
+
+    return ret;
+}
+
+/**
+ * read a single audio or video packet
+ * @param s demuxer context
+ * @param pkt the packet to be filled
+ * @return 0 on success, AVERROR otherwise
+ */
+static int rl2_read_packet(AVFormatContext *s,
+                            AVPacket *pkt)
+{
+    Rl2DemuxContext *rl2 = s->priv_data;
+    ByteIOContext *pb = s->pb;
+    AVIndexEntry *sample = NULL;
+    int i;
+    int ret = 0;
+    int stream_id = -1;
+    int64_t pos = INT64_MAX;
+
+    /** check if there is a valid video or audio entry that can be used */
+    for(i=0; i<s->nb_streams; i++){
+        if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
+              && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
+            sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
+            pos= sample->pos;
+            stream_id= i;
+        }
+    }
+
+    if(stream_id == -1)
+        return AVERROR(EIO);
+
+    ++rl2->index_pos[stream_id];
+
+    /** position the stream (will probably be there anyway) */
+    url_fseek(pb, sample->pos, SEEK_SET);
+
+    /** fill the packet */
+    ret = av_get_packet(pb, pkt, sample->size);
+    if(ret != sample->size){
+        av_free_packet(pkt);
+        return AVERROR(EIO);
+    }
+
+    pkt->stream_index = stream_id;
+    pkt->pts = sample->timestamp;
+
+    return ret;
+}
+
+/**
+ * seek to a new timestamp
+ * @param s demuxer context
+ * @param stream_index index of the stream that should be seeked
+ * @param timestamp wanted timestamp
+ * @param flags direction and seeking mode
+ * @return 0 on success, -1 otherwise
+ */
+static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+    AVStream *st = s->streams[stream_index];
+    Rl2DemuxContext *rl2 = s->priv_data;
+    int i;
+    int index = av_index_search_timestamp(st, timestamp, flags);
+    if(index < 0)
+        return -1;
+
+    rl2->index_pos[stream_index] = index;
+    timestamp = st->index_entries[index].timestamp;
+
+    for(i=0; i < s->nb_streams; i++){
+        AVStream *st2 = s->streams[i];
+        index = av_index_search_timestamp(st2,
+                    av_rescale_q(timestamp, st->time_base, st2->time_base),
+                    flags | AVSEEK_FLAG_BACKWARD);
+
+        if(index < 0)
+            index = 0;
+
+        rl2->index_pos[i] = index;
+    }
+
+    return 0;
+}
+
+AVInputFormat rl2_demuxer = {
+    "rl2",
+    "rl2 format",
+    sizeof(Rl2DemuxContext),
+    rl2_probe,
+    rl2_read_header,
+    rl2_read_packet,
+    NULL,
+    rl2_read_seek,
+};
+