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authorAnssi Hannula <anssi.hannula@iki.fi>2007-04-07 14:25:25 +0000
committerDiego Biurrun <diego@biurrun.de>2007-04-07 14:25:25 +0000
commit9a0ddd09e737545711e209591bc95891e3615543 (patch)
tree09b2c968c21b09a67ebcf166fc7f983a2cd2875f /libavformat/c93.c
parentfe0372296ac6f63c9e1f88d47a05f2918876119c (diff)
downloadffmpeg-9a0ddd09e737545711e209591bc95891e3615543.tar.gz
Interplay C93 demuxer and video decoder
patch by Anssi Hannula, anssi.hannula gmail com Originally committed as revision 8643 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavformat/c93.c')
-rw-r--r--libavformat/c93.c202
1 files changed, 202 insertions, 0 deletions
diff --git a/libavformat/c93.c b/libavformat/c93.c
new file mode 100644
index 0000000000..86f1253985
--- /dev/null
+++ b/libavformat/c93.c
@@ -0,0 +1,202 @@
+/*
+ * Interplay C93 demuxer
+ * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
+ *
+ * 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 "voc.h"
+
+typedef struct {
+ uint16_t index;
+ uint8_t length;
+ uint8_t frames;
+} C93BlockRecord;
+
+typedef struct {
+ voc_dec_context_t voc;
+
+ C93BlockRecord block_records[512];
+ int current_block;
+
+ uint32_t frame_offsets[32];
+ int current_frame;
+ int next_pkt_is_audio;
+
+ AVStream *audio;
+} C93DemuxContext;
+
+static int c93_probe(AVProbeData *p)
+{
+ if (p->buf_size < 13)
+ return 0;
+
+ if (p->buf[0] == 0x01 && p->buf[1] == 0x00 &&
+ p->buf[4] == 0x01 + p->buf[2] &&
+ p->buf[8] == p->buf[4] + p->buf[6] &&
+ p->buf[12] == p->buf[8] + p->buf[10])
+ return AVPROBE_SCORE_MAX;
+
+ return 0;
+}
+
+static int c93_read_header(AVFormatContext *s,
+ AVFormatParameters *ap)
+{
+ AVStream *video;
+ ByteIOContext *pb = &s->pb;
+ C93DemuxContext *c93 = s->priv_data;
+ int i;
+ int framecount = 0;
+
+ for (i = 0; i < 512; i++) {
+ c93->block_records[i].index = get_le16(pb);
+ c93->block_records[i].length = get_byte(pb);
+ c93->block_records[i].frames = get_byte(pb);
+ if (c93->block_records[i].frames > 32) {
+ av_log(s, AV_LOG_ERROR, "too many frames in block\n");
+ return AVERROR_INVALIDDATA;
+ }
+ framecount += c93->block_records[i].frames;
+ }
+
+ /* Audio streams are added if audio packets are found */
+ s->ctx_flags |= AVFMTCTX_NOHEADER;
+
+ video = av_new_stream(s, 0);
+ if (!video)
+ return AVERROR_NOMEM;
+
+ video->codec->codec_type = CODEC_TYPE_VIDEO;
+ video->codec->codec_id = CODEC_ID_C93;
+ video->codec->width = 320;
+ video->codec->height = 192;
+ /* 4:3 320x200 with 8 empty lines */
+ video->codec->sample_aspect_ratio = (AVRational) { 5, 6 };
+ video->time_base = (AVRational) { 2, 25 };
+ video->nb_frames = framecount;
+ video->duration = framecount;
+ video->start_time = 0;
+
+ c93->current_block = 0;
+ c93->current_frame = 0;
+ c93->next_pkt_is_audio = 0;
+ return 0;
+}
+
+#define C93_HAS_PALETTE 0x01
+#define C93_FIRST_FRAME 0x02
+
+static int c93_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ ByteIOContext *pb = &s->pb;
+ C93DemuxContext *c93 = s->priv_data;
+ C93BlockRecord *br = &c93->block_records[c93->current_block];
+ int datasize;
+ int ret, i;
+
+ if (c93->next_pkt_is_audio) {
+ c93->current_frame++;
+ c93->next_pkt_is_audio = 0;
+ datasize = get_le16(pb);
+ if (datasize > 42) {
+ if (!c93->audio) {
+ c93->audio = av_new_stream(s, 1);
+ if (!c93->audio)
+ return AVERROR_NOMEM;
+ c93->audio->codec->codec_type = CODEC_TYPE_AUDIO;
+ }
+ url_fskip(pb, 26); /* VOC header */
+ ret = voc_get_packet(s, pkt, c93->audio, datasize - 26);
+ if (ret > 0) {
+ pkt->stream_index = 1;
+ pkt->flags |= PKT_FLAG_KEY;
+ return ret;
+ }
+ }
+ }
+ if (c93->current_frame >= br->frames) {
+ if (c93->current_block >= 511 || !br[1].length)
+ return AVERROR_IO;
+ br++;
+ c93->current_block++;
+ c93->current_frame = 0;
+ }
+
+ if (c93->current_frame == 0) {
+ url_fseek(pb, br->index * 2048, SEEK_SET);
+ for (i = 0; i < 32; i++) {
+ c93->frame_offsets[i] = get_le32(pb);
+ }
+ }
+
+ url_fseek(pb,br->index * 2048 +
+ c93->frame_offsets[c93->current_frame], SEEK_SET);
+ datasize = get_le16(pb); /* video frame size */
+
+ ret = av_new_packet(pkt, datasize + 768 + 1);
+ if (ret < 0)
+ return ret;
+ pkt->data[0] = 0;
+ pkt->size = datasize + 1;
+
+ ret = get_buffer(pb, pkt->data + 1, datasize);
+ if (ret < datasize) {
+ ret = AVERROR_IO;
+ goto fail;
+ }
+
+ datasize = get_le16(pb); /* palette size */
+ if (datasize) {
+ if (datasize != 768) {
+ av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize);
+ ret = AVERROR_INVALIDDATA;
+ goto fail;
+ }
+ pkt->data[0] |= C93_HAS_PALETTE;
+ ret = get_buffer(pb, pkt->data + pkt->size, datasize);
+ if (ret < datasize) {
+ ret = AVERROR_IO;
+ goto fail;
+ }
+ pkt->size += 768;
+ }
+ pkt->stream_index = 0;
+ c93->next_pkt_is_audio = 1;
+
+ /* only the first frame is guaranteed to not reference previous frames */
+ if (c93->current_block == 0 && c93->current_frame == 0) {
+ pkt->flags |= PKT_FLAG_KEY;
+ pkt->data[0] |= C93_FIRST_FRAME;
+ }
+ return 0;
+
+ fail:
+ av_free_packet(pkt);
+ return ret;
+}
+
+AVInputFormat c93_demuxer = {
+ "c93",
+ "Interplay C93",
+ sizeof(C93DemuxContext),
+ c93_probe,
+ c93_read_header,
+ c93_read_packet,
+};