--- /dev/null
+/*
+ * MPEG2 transport stream (aka DVB) demux
+ * Copyright (c) 2002 Gerard Lantau.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include "avformat.h"
+
+#define TS_FEC_PACKET_SIZE 204
+#define TS_PACKET_SIZE 188
+#define NB_PID_MAX 8192
+
+enum MpegTSState {
+ MPEGTS_HEADER = 0,
+ MPEGTS_PESHEADER_FILL,
+ MPEGTS_PESHEADER_FLAGS,
+ MPEGTS_PESHEADER_SIZE,
+ MPEGTS_PESHEADER_READ,
+ MPEGTS_PAYLOAD,
+ MPEGTS_SKIP,
+};
+
+/* enough for PES header + length */
+#define MAX_HEADER_SIZE 6
+
+typedef struct MpegTSStream {
+ int pid;
+ enum MpegTSState state;
+ int last_cc; /* last cc code (-1 if first packet) */
+ /* used to get the format */
+ int header_size;
+ int payload_size;
+ int pes_header_size;
+ AVStream *st;
+ unsigned char header[MAX_HEADER_SIZE];
+} MpegTSStream;
+
+typedef struct MpegTSContext {
+ int raw_packet_size; /* raw packet size, including FEC if present */
+ MpegTSStream *pids[NB_PID_MAX];
+} MpegTSContext;
+
+/* autodetect fec presence. Must have at least 1024 bytes */
+static int get_packet_size(const unsigned char *buf, int size)
+{
+ int i;
+
+ if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
+ return -1;
+ for(i=0;i<5;i++) {
+ if (buf[i * TS_PACKET_SIZE] != 0x47)
+ goto try_fec;
+ }
+ return TS_PACKET_SIZE;
+ try_fec:
+ for(i=0;i<5;i++) {
+ if (buf[i * TS_FEC_PACKET_SIZE] != 0x47)
+ return -1;
+ }
+ return TS_FEC_PACKET_SIZE;
+}
+
+static int mpegts_probe(AVProbeData *p)
+{
+ int size;
+ size = get_packet_size(p->buf, p->buf_size);
+ if (size < 0)
+ return 0;
+ return AVPROBE_SCORE_MAX;
+}
+
+static int mpegts_read_header(AVFormatContext *s,
+ AVFormatParameters *ap)
+{
+ MpegTSContext *ts = s->priv_data;
+ ByteIOContext *pb = &s->pb;
+ unsigned char buf[1024];
+ int len;
+ INT64 pos;
+
+ /* read the first 1024 bytes to get packet size */
+ pos = url_ftell(pb);
+ len = get_buffer(pb, buf, sizeof(buf));
+ if (len != sizeof(buf))
+ goto fail;
+ ts->raw_packet_size = get_packet_size(buf, sizeof(buf));
+ if (ts->raw_packet_size <= 0)
+ goto fail;
+ /* go again to the start */
+ url_fseek(pb, pos, SEEK_SET);
+ return 0;
+ fail:
+ return -1;
+}
+
+/* return non zero if a packet could be constructed */
+static int mpegts_push_data(AVFormatContext *s, MpegTSStream *tss,
+ AVPacket *pkt,
+ const unsigned char *buf, int buf_size, int is_start)
+{
+ AVStream *st;
+ const unsigned char *p;
+ int len, code, codec_type, codec_id;
+
+ if (is_start) {
+ tss->state = MPEGTS_HEADER;
+ tss->header_size = 0;
+ }
+ p = buf;
+ while (buf_size > 0) {
+ len = buf_size;
+ switch(tss->state) {
+ case MPEGTS_HEADER:
+ if (len > MAX_HEADER_SIZE - tss->header_size)
+ len = MAX_HEADER_SIZE - tss->header_size;
+ memcpy(tss->header, p, len);
+ tss->header_size += len;
+ p += len;
+ buf_size -= len;
+ if (tss->header_size == MAX_HEADER_SIZE) {
+ /* we got all the PES or section header. We can now
+ decide */
+#if 0
+ av_hex_dump(tss->header, tss->header_size);
+#endif
+ if (tss->header[0] == 0x00 && tss->header[1] == 0x00 &&
+ tss->header[2] == 0x01) {
+ /* it must be an mpeg2 PES stream */
+ /* XXX: add AC3 support */
+ code = tss->header[3] | 0x100;
+ if (!((code >= 0x1c0 && code <= 0x1df) ||
+ (code >= 0x1e0 && code <= 0x1ef)))
+ goto skip;
+ if (!tss->st) {
+ /* allocate stream */
+ if (code >= 0x1c0 && code <= 0x1df) {
+ codec_type = CODEC_TYPE_AUDIO;
+ codec_id = CODEC_ID_MP2;
+ } else {
+ codec_type = CODEC_TYPE_VIDEO;
+ codec_id = CODEC_ID_MPEG1VIDEO;
+ }
+ st = av_new_stream(s, tss->pid);
+ if (st) {
+ st->priv_data = tss;
+ st->codec.codec_type = codec_type;
+ st->codec.codec_id = codec_id;
+ tss->st = st;
+ }
+ }
+ tss->state = MPEGTS_PESHEADER_FILL;
+ tss->payload_size = (tss->header[4] << 8) | tss->header[5];
+ if (tss->payload_size == 0)
+ tss->payload_size = 65536;
+ } else {
+ /* otherwise, it should be a table */
+ /* skip packet */
+ skip:
+ tss->state = MPEGTS_SKIP;
+ continue;
+ }
+ }
+ break;
+ /**********************************************/
+ /* PES packing parsing */
+ case MPEGTS_PESHEADER_FILL:
+ /* skip filling */
+ code = *p++;
+ buf_size--;
+ tss->payload_size--;
+ if (code != 0xff) {
+ if ((code & 0xc0) != 0x80)
+ goto skip;
+ tss->state = MPEGTS_PESHEADER_FLAGS;
+ }
+ break;
+ case MPEGTS_PESHEADER_FLAGS:
+ code = *p++;
+ buf_size--;
+ tss->payload_size--;
+ tss->state = MPEGTS_PESHEADER_SIZE;
+ break;
+ case MPEGTS_PESHEADER_SIZE:
+ tss->pes_header_size = *p++;
+ buf_size--;
+ tss->payload_size--;
+ tss->state = MPEGTS_PESHEADER_READ;
+ break;
+ case MPEGTS_PESHEADER_READ:
+ /* currently we do nothing except skipping */
+ if (len > tss->pes_header_size)
+ len = tss->pes_header_size;
+ p += len;
+ buf_size -= len;
+ tss->pes_header_size -= len;
+ tss->payload_size -= len;
+ if (tss->pes_header_size == 0)
+ tss->state = MPEGTS_PAYLOAD;
+ break;
+ case MPEGTS_PAYLOAD:
+ if (len > tss->payload_size)
+ len = tss->payload_size;
+ if (len > 0) {
+ if (tss->st && av_new_packet(pkt, buf_size) == 0) {
+ memcpy(pkt->data, p, buf_size);
+ pkt->stream_index = tss->st->index;
+ return 1;
+ }
+ tss->payload_size -= len;
+ }
+ buf_size = 0;
+ break;
+ case MPEGTS_SKIP:
+ buf_size = 0;
+ break;
+ }
+ }
+ return 0;
+}
+
+static int mpegts_read_packet(AVFormatContext *s,
+ AVPacket *pkt)
+{
+ MpegTSContext *ts = s->priv_data;
+ MpegTSStream *tss;
+ ByteIOContext *pb = &s->pb;
+ unsigned char packet[TS_FEC_PACKET_SIZE];
+ int len, pid, cc, cc_ok, afc;
+ const unsigned char *p;
+
+ for(;;) {
+ len = get_buffer(pb, packet, ts->raw_packet_size);
+ if (len != ts->raw_packet_size)
+ return AVERROR_IO;
+ /* check paquet sync byte */
+ /* XXX: accept to resync ? */
+ if (packet[0] != 0x47)
+ return AVERROR_INVALIDDATA;
+
+ pid = ((packet[1] & 0x1f) << 8) | packet[2];
+ tss = ts->pids[pid];
+ if (tss == NULL) {
+ /* if no pid found, then add a pid context */
+ tss = av_mallocz(sizeof(MpegTSStream));
+ if (!tss)
+ continue;
+ ts->pids[pid] = tss;
+ tss->pid = pid;
+ tss->last_cc = -1;
+ // printf("new pid=0x%x\n", pid);
+ }
+
+ /* continuity check (currently not used) */
+ cc = (packet[3] & 0xf);
+ cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc));
+ tss->last_cc = cc;
+
+ /* skip adaptation field */
+ afc = (packet[3] >> 4) & 3;
+ p = packet + 4;
+ if (afc == 0) /* reserved value */
+ continue;
+ if (afc == 2) /* adaptation field only */
+ continue;
+ if (afc == 3) {
+ /* skip adapation field */
+ p += p[0] + 1;
+ }
+ /* if past the end of packet, ignore */
+ if (p >= packet + TS_PACKET_SIZE)
+ continue;
+
+ if (mpegts_push_data(s, tss, pkt, p, TS_PACKET_SIZE - (p - packet),
+ packet[1] & 0x40))
+ break;
+ }
+ return 0;
+}
+
+static int mpegts_read_close(AVFormatContext *s)
+{
+ MpegTSContext *ts = s->priv_data;
+ int i;
+ for(i=0;i<NB_PID_MAX;i++)
+ av_freep(ts->pids[i]);
+ return 0;
+}
+
+AVInputFormat mpegts_demux = {
+ "mpegts",
+ "MPEG2 transport stream format",
+ sizeof(MpegTSContext),
+ mpegts_probe,
+ mpegts_read_header,
+ mpegts_read_packet,
+ mpegts_read_close,
+ flags: AVFMT_NOHEADER | AVFMT_SHOW_IDS,
+};
+
+int mpegts_init(void)
+{
+ av_register_input_format(&mpegts_demux);
+ return 0;
+}
projects / frescor / ffmpeg.git / commitdiff