mpeg2dec.c

mpeg2 decoder filter过滤服务端

		    bytes = (x);				\
		} else {					\
		    memcpy (header + bytes, buf, end - buf);	\
		    state_bytes = bytes + end - buf;		\
		    return 0;					\
		}						\
	    } else {						\
		memcpy (head_buf, header, bytes);		\
		state = DEMUX_HEADER;				\
		state_bytes = bytes;				\
		return 0;					\
	    }							\
	}							\
    } while (0)

#define DONEBYTES(x)		\
    do {			\
	if (header != head_buf)	\
	    buf = header + (x);	\
    } while (0)

    if (flags & DEMUX_PAYLOAD_START)
	goto payload_start;
    switch (state) {
    case DEMUX_HEADER:
	if (state_bytes > 0) {
	    header = head_buf;
	    bytes = state_bytes;
	    goto continue_header;
	}
	break;
    case DEMUX_DATA:
	if (demux_pid || (state_bytes > end - buf)) {
	    decode_mpeg2 (buf, end);
	    state_bytes -= end - buf;
	    return 0;
	}
	decode_mpeg2 (buf, buf + state_bytes);
	buf += state_bytes;
	break;
    case DEMUX_SKIP:
	if (demux_pid || (state_bytes > end - buf)) {
	    state_bytes -= end - buf;
	    return 0;
	}
	buf += state_bytes;
	break;
    }

    while (1) {
	if (demux_pid) {
	    state = DEMUX_SKIP;
	    return 0;
	}
    payload_start:
	header = buf;
	bytes = end - buf;
    continue_header:
	NEEDBYTES (4);
	if (header[0] || header[1] || (header[2] != 1)) {
	    if (demux_pid) {
		state = DEMUX_SKIP;
		return 0;
	    } else if (header != head_buf) {
		buf++;
		goto payload_start;
	    } else {
		header[0] = header[1];
		header[1] = header[2];
		header[2] = header[3];
		bytes = 3;
		goto continue_header;
	    }
	}
	if (demux_pid) {
	    if ((header[3] >= 0xe0) && (header[3] <= 0xef))
		goto pes;
	    fprintf (stderr, "bad stream id %x\n", header[3]);
	    exit (1);
	}
	switch (header[3]) {
	case 0xb9:	/* program end code */
	    /* DONEBYTES (4); */
	    /* break;         */
	    return 1;
	case 0xba:	/* pack header */
	    NEEDBYTES (5);
	    if ((header[4] & 0xc0) == 0x40) {	/* mpeg2 */
		NEEDBYTES (14);
		len = 14 + (header[13] & 7);
		NEEDBYTES (len);
		DONEBYTES (len);
		/* header points to the mpeg2 pack header */
	    } else if ((header[4] & 0xf0) == 0x20) {	/* mpeg1 */
		NEEDBYTES (12);
		DONEBYTES (12);
		/* header points to the mpeg1 pack header */
	    } else {
		fprintf (stderr, "weird pack header\n");
		DONEBYTES (5);
	    }
	    break;
	default:
	    if (header[3] == demux_track) {
	    pes:
		NEEDBYTES (7);
		if ((header[6] & 0xc0) == 0x80) {	/* mpeg2 */
		    NEEDBYTES (9);
		    len = 9 + header[8];
		    NEEDBYTES (len);
		    /* header points to the mpeg2 pes header */
		    if (header[7] & 0x80) {
			uint32_t pts, dts;

			pts = (((header[9] >> 1) << 30) |
			       (header[10] << 22) | ((header[11] >> 1) << 15) |
			       (header[12] << 7) | (header[13] >> 1));
			dts = (!(header[7] & 0x40) ? pts :
			       (((header[14] >> 1) << 30) |
				(header[15] << 22) |
				((header[16] >> 1) << 15) |
				(header[17] << 7) | (header[18] >> 1)));
			mpeg2_tag_picture (mpeg2dec, pts, dts);
		    }
		} else {	/* mpeg1 */
		    int len_skip;
		    uint8_t * ptsbuf;

		    len = 7;
		    while (header[len - 1] == 0xff) {
			len++;
			NEEDBYTES (len);
			if (len > 23) {
			    fprintf (stderr, "too much stuffing\n");
			    break;
			}
		    }
		    if ((header[len - 1] & 0xc0) == 0x40) {
			len += 2;
			NEEDBYTES (len);
		    }
		    len_skip = len;
		    len += mpeg1_skip_table[header[len - 1] >> 4];
		    NEEDBYTES (len);
		    /* header points to the mpeg1 pes header */
		    ptsbuf = header + len_skip;
		    if ((ptsbuf[-1] & 0xe0) == 0x20) {
			uint32_t pts, dts;

			pts = (((ptsbuf[-1] >> 1) << 30) |
			       (ptsbuf[0] << 22) | ((ptsbuf[1] >> 1) << 15) |
			       (ptsbuf[2] << 7) | (ptsbuf[3] >> 1));
			dts = (((ptsbuf[-1] & 0xf0) != 0x30) ? pts :
			       (((ptsbuf[4] >> 1) << 30) |
				(ptsbuf[5] << 22) | ((ptsbuf[6] >> 1) << 15) |
				(ptsbuf[7] << 7) | (ptsbuf[18] >> 1)));
			mpeg2_tag_picture (mpeg2dec, pts, dts);
		    }
		}
		DONEBYTES (len);
		bytes = 6 + (header[4] << 8) + header[5] - len;
		if (demux_pid || (bytes > end - buf)) {
		    decode_mpeg2 (buf, end);
		    state = DEMUX_DATA;
		    state_bytes = bytes - (end - buf);
		    return 0;
		} else if (bytes > 0) {
		    decode_mpeg2 (buf, buf + bytes);
		    buf += bytes;
		}
	    } else if (header[3] < 0xb9) {
		fprintf (stderr,
			 "looks like a video stream, not system stream\n");
		DONEBYTES (4);
	    } else {
		NEEDBYTES (6);
		DONEBYTES (6);
		bytes = (header[4] << 8) + header[5];
		if (bytes > end - buf) {
		    state = DEMUX_SKIP;
		    state_bytes = bytes - (end - buf);
		    return 0;
		}
		buf += bytes;
	    }
	}
    }
}

static void ps_loop (void)
{
    uint8_t * buffer = (uint8_t *) malloc (buffer_size);
    uint8_t * end;

    if (buffer == NULL)
	exit (1);
    do {
	end = buffer + fread (buffer, 1, buffer_size, in_file);
	if (demux (buffer, end, 0))
	    break;	/* hit program_end_code */
    } while (end == buffer + buffer_size && !sigint);
    free (buffer);
}

static int pva_demux (uint8_t * buf, uint8_t * end)
{
    static int state = DEMUX_SKIP;
    static int state_bytes = 0;
    static uint8_t head_buf[15];

    uint8_t * header;
    int bytes;
    int len;

    switch (state) {
    case DEMUX_HEADER:
        if (state_bytes > 0) {
            header = head_buf;
            bytes = state_bytes;
            goto continue_header;
        }
        break;
    case DEMUX_DATA:
        if (state_bytes > end - buf) {
            decode_mpeg2 (buf, end);
            state_bytes -= end - buf;
            return 0;
        }
        decode_mpeg2 (buf, buf + state_bytes);
        buf += state_bytes;
        break;
    case DEMUX_SKIP:
        if (state_bytes > end - buf) {
            state_bytes -= end - buf;
            return 0;
        }
        buf += state_bytes;
        break;
    }

    while (1) {
    payload_start:
	header = buf;
	bytes = end - buf;
    continue_header:
	NEEDBYTES (2);
	if (header[0] != 0x41 || header[1] != 0x56) {
	    if (header != head_buf) {
		buf++;
		goto payload_start;
	    } else {
		header[0] = header[1];
		bytes = 1;
		goto continue_header;
	    }
	}
	NEEDBYTES (8);
	if (header[2] != 1) {
	    DONEBYTES (8);
	    bytes = (header[6] << 8) + header[7];
	    if (bytes > end - buf) {
		state = DEMUX_SKIP;
		state_bytes = bytes - (end - buf);
		return 0;
	    } 
	    buf += bytes; 
	} else {
	    len = 8;
	    if (header[5] & 0x10) {
		len = 12 + (header[5] & 3);
		NEEDBYTES (len);
		decode_mpeg2 (header + 12, header + len);
		mpeg2_tag_picture (mpeg2dec,
				   ((header[8] << 24) | (header[9] << 16) |
				    (header[10] << 8) | header[11]), 0);
	    }
	    DONEBYTES (len);
	    bytes = (header[6] << 8) + header[7] + 8 - len;
	    if (bytes > end - buf) {
		decode_mpeg2 (buf, end);
		state = DEMUX_DATA;
		state_bytes = bytes - (end - buf);
		return 0;
	    } else if (bytes > 0) {
		decode_mpeg2 (buf, buf + bytes);
		buf += bytes;
	    }
	}
    }
}

static void pva_loop (void)
{
    uint8_t * buffer = (uint8_t *) malloc (buffer_size);
    uint8_t * end;

    if (buffer == NULL)
	exit (1);
    do {
	end = buffer + fread (buffer, 1, buffer_size, in_file);
	pva_demux (buffer, end);
    } while (end == buffer + buffer_size && !sigint);
    free (buffer);
}

static void ts_loop (void)
{
    uint8_t * buffer = (uint8_t *) malloc (buffer_size);
    uint8_t * buf;
    uint8_t * nextbuf;
    uint8_t * data;
    uint8_t * end;
    int pid;

    if (buffer == NULL || buffer_size < 188)
	exit (1);
    buf = buffer;
    do {
	end = buf + fread (buf, 1, buffer + buffer_size - buf, in_file);
	buf = buffer;
	for (; (nextbuf = buf + 188) <= end; buf = nextbuf) {
	    if (*buf != 0x47) {
		fprintf (stderr, "bad sync byte\n");
		nextbuf = buf + 1;
		continue;
	    }
	    pid = ((buf[1] << 8) + buf[2]) & 0x1fff;
	    if (pid != demux_pid)
		continue;
	    data = buf + 4;
	    if (buf[3] & 0x20) {	/* buf contains an adaptation field */
		data = buf + 5 + buf[4];
		if (data > nextbuf)
		    continue;
	    }
	    if (buf[3] & 0x10)
		demux (data, nextbuf,
		       (buf[1] & 0x40) ? DEMUX_PAYLOAD_START : 0);
	}
	if (end != buffer + buffer_size)
	    break;
	memcpy (buffer, buf, end - buf);
	buf = buffer + (end - buf);
    } while (!sigint);
    free (buffer);
}

static void es_loop (void)
{
    uint8_t * buffer = (uint8_t *) malloc (buffer_size);
    uint8_t * end;

    if (buffer == NULL)
	exit (1);
    do {
	end = buffer + fread (buffer, 1, buffer_size, in_file);
	decode_mpeg2 (buffer, end);
    } while (end == buffer + buffer_size && !sigint);
    free (buffer);
}

int main (int argc, char ** argv)
{
#ifdef HAVE_IO_H
    setmode (fileno (stdin), O_BINARY);
    setmode (fileno (stdout), O_BINARY);
#endif

    fprintf (stderr, PACKAGE"-"VERSION
	     " - by Michel Lespinasse <[e-mail]> and Aaron Holtzman\n");

    handle_args (argc, argv);

    output = output_open ();
    if (output == NULL) {
	fprintf (stderr, "Can not open output\n");
	return 1;
    }
    mpeg2dec = mpeg2_init ();
    if (mpeg2dec == NULL)
	exit (1);
    mpeg2_malloc_hooks (malloc_hook, NULL);

    if (demux_pva)
	pva_loop ();
    else if (demux_pid)
	ts_loop ();
    else if (demux_track)
	ps_loop ();
    else
	es_loop ();

    mpeg2_close (mpeg2dec);
    if (output->close)
	output->close (output);
    print_fps (1);
    fclose (in_file);
    return 0;
}