libavformat/rtpdec_asf.c - third_party/ffmpeg - Git at Google

 /*
  * Microsoft RTP/ASF support.
  * Copyright (c) 2008 Ronald S. Bultje
  *
  * 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
  */

 /**
  * @file
  * @brief Microsoft RTP/ASF support
  * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
  */

 #include "libavutil/avassert.h"
 #include "libavutil/base64.h"
 #include "libavutil/avstring.h"
 #include "libavutil/intreadwrite.h"
 #include "rtp.h"
 #include "rtpdec_formats.h"
 #include "rtsp.h"
 #include "asf.h"
 #include "avio_internal.h"
 #include "internal.h"

 /**
  * From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
  * contain any padding. Unfortunately, the header min/max_pktsize are not
  * updated (thus making min_pktsize invalid). Here, we "fix" these faulty
  * min_pktsize values in the ASF file header.
  * @return 0 on success, <0 on failure (currently -1).
  */
 static int rtp_asf_fix_header(uint8_t *buf, int len)
 {
     uint8_t *p = buf, *end = buf + len;

     if (len < sizeof(ff_asf_guid) * 2 + 22 ||
         memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
         return -1;
     }
     p += sizeof(ff_asf_guid) + 14;
     do {
         uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
         int skip = 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
         if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
             if (chunksize > end - p)
                 return -1;
             p += chunksize;
             continue;
         }

         if (end - p < 8 + skip)
             break;
         /* skip most of the file header, to min_pktsize */
         p += skip;
         if (AV_RL32(p) == AV_RL32(p + 4)) {
             /* and set that to zero */
             AV_WL32(p, 0);
             return 0;
         }
         break;
     } while (end - p >= sizeof(ff_asf_guid) + 8);

     return -1;
 }

 /**
  * The following code is basically a buffered AVIOContext,
  * with the added benefit of returning -EAGAIN (instead of 0)
  * on packet boundaries, such that the ASF demuxer can return
  * safely and resume business at the next packet.
  */
 static int packetizer_read(void *opaque, uint8_t *buf, int buf_size)
 {
     return AVERROR(EAGAIN);
 }

 static void init_packetizer(AVIOContext *pb, uint8_t *buf, int len)
 {
     ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);

     /* this "fills" the buffer with its current content */
     pb->pos     = len;
     pb->buf_end = buf + len;
 }

 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p)
 {
     int ret = 0;
     if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
         AVIOContext pb = { 0 };
         RTSPState *rt = s->priv_data;
         AVDictionary *opts = NULL;
         int len = strlen(p) * 6 / 8;
         char *buf = av_mallocz(len);
         AVInputFormat *iformat;

         if (!buf)
             return AVERROR(ENOMEM);
         av_base64_decode(buf, p, len);

         if (rtp_asf_fix_header(buf, len) < 0)
             av_log(s, AV_LOG_ERROR,
                    "Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
         init_packetizer(&pb, buf, len);
         if (rt->asf_ctx) {
             avformat_close_input(&rt->asf_ctx);
         }

         if (!(iformat = av_find_input_format("asf")))
             return AVERROR_DEMUXER_NOT_FOUND;

         rt->asf_ctx = avformat_alloc_context();
         if (!rt->asf_ctx) {
             av_free(buf);
             return AVERROR(ENOMEM);
         }
         rt->asf_ctx->pb      = &pb;
         av_dict_set(&opts, "no_resync_search", "1", 0);

         if ((ret = ff_copy_whiteblacklists(rt->asf_ctx, s)) < 0) {
             av_dict_free(&opts);
             return ret;
         }

         ret = avformat_open_input(&rt->asf_ctx, "", iformat, &opts);
         av_dict_free(&opts);
         if (ret < 0) {
             av_free(pb.buffer);
             return ret;
         }
         av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
         rt->asf_pb_pos = avio_tell(&pb);
         av_free(pb.buffer);
         rt->asf_ctx->pb = NULL;
     }
     return ret;
 }

 static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
                                  PayloadContext *asf, const char *line)
 {
     if (stream_index < 0)
         return 0;
     if (av_strstart(line, "stream:", &line)) {
         RTSPState *rt = s->priv_data;

         s->streams[stream_index]->id = strtol(line, NULL, 10);

         if (rt->asf_ctx) {
             int i;

             for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
                 if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
                     avcodec_parameters_copy(s->streams[stream_index]->codecpar,
                                             rt->asf_ctx->streams[i]->codecpar);
                     s->streams[stream_index]->need_parsing =
                         rt->asf_ctx->streams[i]->need_parsing;
                     avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
                 }
            }
         }
     }

     return 0;
 }

 struct PayloadContext {
     AVIOContext *pktbuf, pb;
     uint8_t *buf;
 };

 /**
  * @return 0 when a packet was written into /p pkt, and no more data is left;
  *         1 when a packet was written into /p pkt, and more packets might be left;
  *        <0 when not enough data was provided to return a full packet, or on error.
  */
 static int asfrtp_parse_packet(AVFormatContext *s, PayloadContext *asf,
                                AVStream *st, AVPacket *pkt,
                                uint32_t *timestamp,
                                const uint8_t *buf, int len, uint16_t seq,
                                int flags)
 {
     AVIOContext *pb = &asf->pb;
     int res, mflags, len_off;
     RTSPState *rt = s->priv_data;

     if (!rt->asf_ctx)
         return -1;

     if (len > 0) {
         int off, out_len = 0;

         if (len < 4)
             return -1;

         av_freep(&asf->buf);

         ffio_init_context(pb, (uint8_t *)buf, len, 0, NULL, NULL, NULL, NULL);

         while (avio_tell(pb) + 4 < len) {
             int start_off = avio_tell(pb);

             mflags = avio_r8(pb);
             len_off = avio_rb24(pb);
             if (mflags & 0x20)   /**< relative timestamp */
                 avio_skip(pb, 4);
             if (mflags & 0x10)   /**< has duration */
                 avio_skip(pb, 4);
             if (mflags & 0x8)    /**< has location ID */
                 avio_skip(pb, 4);
             off = avio_tell(pb);

             if (!(mflags & 0x40)) {
                 /**
                  * If 0x40 is not set, the len_off field specifies an offset
                  * of this packet's payload data in the complete (reassembled)
                  * ASF packet. This is used to spread one ASF packet over
                  * multiple RTP packets.
                  */
                 if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
                     ffio_free_dyn_buf(&asf->pktbuf);
                 }
                 if (!len_off && !asf->pktbuf &&
                     (res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
                     return res;
                 if (!asf->pktbuf)
                     return AVERROR(EIO);

                 avio_write(asf->pktbuf, buf + off, len - off);
                 avio_skip(pb, len - off);
                 if (!(flags & RTP_FLAG_MARKER))
                     return -1;
                 out_len     = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
                 asf->pktbuf = NULL;
             } else {
                 /**
                  * If 0x40 is set, the len_off field specifies the length of
                  * the next ASF packet that can be read from this payload
                  * data alone. This is commonly the same as the payload size,
                  * but could be less in case of packet splitting (i.e.
                  * multiple ASF packets in one RTP packet).
                  */

                 int cur_len = start_off + len_off - off;
                 int prev_len = out_len;
                 out_len += cur_len;
                 if (FFMIN(cur_len, len - off) < 0)
                     return -1;
                 if ((res = av_reallocp(&asf->buf, out_len)) < 0)
                     return res;
                 memcpy(asf->buf + prev_len, buf + off,
                        FFMIN(cur_len, len - off));
                 avio_skip(pb, cur_len);
             }
         }

         init_packetizer(pb, asf->buf, out_len);
         pb->pos += rt->asf_pb_pos;
         pb->eof_reached = 0;
         rt->asf_ctx->pb = pb;
     }

     for (;;) {
         int i;

         res = ff_read_packet(rt->asf_ctx, pkt);
         rt->asf_pb_pos = avio_tell(pb);
         if (res != 0)
             break;
         for (i = 0; i < s->nb_streams; i++) {
             if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
                 pkt->stream_index = i;
                 return 1; // FIXME: return 0 if last packet
             }
         }
         av_packet_unref(pkt);
     }

     return res == 1 ? -1 : res;
 }

 static void asfrtp_close_context(PayloadContext *asf)
 {
     ffio_free_dyn_buf(&asf->pktbuf);
     av_freep(&asf->buf);
 }

 #define RTP_ASF_HANDLER(n, s, t) \
 const RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
     .enc_name         = s, \
     .codec_type       = t, \
     .codec_id         = AV_CODEC_ID_NONE, \
     .priv_data_size   = sizeof(PayloadContext), \
     .parse_sdp_a_line = asfrtp_parse_sdp_line, \
     .close            = asfrtp_close_context, \
     .parse_packet     = asfrtp_parse_packet,   \
 }

 RTP_ASF_HANDLER(asf_pfv, "x-asf-pf",  AVMEDIA_TYPE_VIDEO);
 RTP_ASF_HANDLER(asf_pfa, "x-asf-pf",  AVMEDIA_TYPE_AUDIO);
	/*
	* Microsoft RTP/ASF support.
	* Copyright (c) 2008 Ronald S. Bultje
	*
	* 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
	*/

	/**
	* @file
	* @brief Microsoft RTP/ASF support
	* @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
	*/

	#include "libavutil/avassert.h"
	#include "libavutil/base64.h"
	#include "libavutil/avstring.h"
	#include "libavutil/intreadwrite.h"
	#include "rtp.h"
	#include "rtpdec_formats.h"
	#include "rtsp.h"
	#include "asf.h"
	#include "avio_internal.h"
	#include "internal.h"

	/**
	* From MSDN 2.2.1.4, we learn that ASF data packets over RTP should not
	* contain any padding. Unfortunately, the header min/max_pktsize are not
	* updated (thus making min_pktsize invalid). Here, we "fix" these faulty
	* min_pktsize values in the ASF file header.
	* @return 0 on success, <0 on failure (currently -1).
	*/
	static int rtp_asf_fix_header(uint8_t *buf, int len)
	{
	uint8_t p = buf, end = buf + len;

	if (len < sizeof(ff_asf_guid) * 2 + 22 \|\|
	memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
	return -1;
	}
	p += sizeof(ff_asf_guid) + 14;
	do {
	uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
	int skip = 6 * 8 + 3 * 4 + sizeof(ff_asf_guid) * 2;
	if (memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
	if (chunksize > end - p)
	return -1;
	p += chunksize;
	continue;
	}

	if (end - p < 8 + skip)
	break;
	/* skip most of the file header, to min_pktsize */
	p += skip;
	if (AV_RL32(p) == AV_RL32(p + 4)) {
	/* and set that to zero */
	AV_WL32(p, 0);
	return 0;
	}
	break;
	} while (end - p >= sizeof(ff_asf_guid) + 8);

	return -1;
	}

	/**
	* The following code is basically a buffered AVIOContext,
	* with the added benefit of returning -EAGAIN (instead of 0)
	* on packet boundaries, such that the ASF demuxer can return
	* safely and resume business at the next packet.
	*/
	static int packetizer_read(void opaque, uint8_t buf, int buf_size)
	{
	return AVERROR(EAGAIN);
	}

	static void init_packetizer(AVIOContext pb, uint8_t buf, int len)
	{
	ffio_init_context(pb, buf, len, 0, NULL, packetizer_read, NULL, NULL);

	/* this "fills" the buffer with its current content */
	pb->pos = len;
	pb->buf_end = buf + len;
	}

	int ff_wms_parse_sdp_a_line(AVFormatContext s, const char p)
	{
	int ret = 0;
	if (av_strstart(p, "pgmpu:data:application/vnd.ms.wms-hdr.asfv1;base64,", &p)) {
	AVIOContext pb = { 0 };
	RTSPState *rt = s->priv_data;
	AVDictionary *opts = NULL;
	int len = strlen(p) * 6 / 8;
	char *buf = av_mallocz(len);
	AVInputFormat *iformat;

	if (!buf)
	return AVERROR(ENOMEM);
	av_base64_decode(buf, p, len);

	if (rtp_asf_fix_header(buf, len) < 0)
	av_log(s, AV_LOG_ERROR,
	"Failed to fix invalid RTSP-MS/ASF min_pktsize\n");
	init_packetizer(&pb, buf, len);
	if (rt->asf_ctx) {
	avformat_close_input(&rt->asf_ctx);
	}

	if (!(iformat = av_find_input_format("asf")))
	return AVERROR_DEMUXER_NOT_FOUND;

	rt->asf_ctx = avformat_alloc_context();
	if (!rt->asf_ctx) {
	av_free(buf);
	return AVERROR(ENOMEM);
	}
	rt->asf_ctx->pb = &pb;
	av_dict_set(&opts, "no_resync_search", "1", 0);

	if ((ret = ff_copy_whiteblacklists(rt->asf_ctx, s)) < 0) {
	av_dict_free(&opts);
	return ret;
	}

	ret = avformat_open_input(&rt->asf_ctx, "", iformat, &opts);
	av_dict_free(&opts);
	if (ret < 0) {
	av_free(pb.buffer);
	return ret;
	}
	av_dict_copy(&s->metadata, rt->asf_ctx->metadata, 0);
	rt->asf_pb_pos = avio_tell(&pb);
	av_free(pb.buffer);
	rt->asf_ctx->pb = NULL;
	}
	return ret;
	}

	static int asfrtp_parse_sdp_line(AVFormatContext *s, int stream_index,
	PayloadContext asf, const char line)
	{
	if (stream_index < 0)
	return 0;
	if (av_strstart(line, "stream:", &line)) {
	RTSPState *rt = s->priv_data;

	s->streams[stream_index]->id = strtol(line, NULL, 10);

	if (rt->asf_ctx) {
	int i;

	for (i = 0; i < rt->asf_ctx->nb_streams; i++) {
	if (s->streams[stream_index]->id == rt->asf_ctx->streams[i]->id) {
	avcodec_parameters_copy(s->streams[stream_index]->codecpar,
	rt->asf_ctx->streams[i]->codecpar);
	s->streams[stream_index]->need_parsing =
	rt->asf_ctx->streams[i]->need_parsing;
	avpriv_set_pts_info(s->streams[stream_index], 32, 1, 1000);
	}
	}
	}
	}

	return 0;
	}

	struct PayloadContext {
	AVIOContext *pktbuf, pb;
	uint8_t *buf;
	};

	/**
	* @return 0 when a packet was written into /p pkt, and no more data is left;
	* 1 when a packet was written into /p pkt, and more packets might be left;
	* <0 when not enough data was provided to return a full packet, or on error.
	*/
	static int asfrtp_parse_packet(AVFormatContext s, PayloadContext asf,
	AVStream st, AVPacket pkt,
	uint32_t *timestamp,
	const uint8_t *buf, int len, uint16_t seq,
	int flags)
	{
	AVIOContext *pb = &asf->pb;
	int res, mflags, len_off;
	RTSPState *rt = s->priv_data;

	if (!rt->asf_ctx)
	return -1;

	if (len > 0) {
	int off, out_len = 0;

	if (len < 4)
	return -1;

	av_freep(&asf->buf);

	ffio_init_context(pb, (uint8_t *)buf, len, 0, NULL, NULL, NULL, NULL);

	while (avio_tell(pb) + 4 < len) {
	int start_off = avio_tell(pb);

	mflags = avio_r8(pb);
	len_off = avio_rb24(pb);
	if (mflags & 0x20) /*< relative timestamp /
	avio_skip(pb, 4);
	if (mflags & 0x10) /*< has duration /
	avio_skip(pb, 4);
	if (mflags & 0x8) /*< has location ID /
	avio_skip(pb, 4);
	off = avio_tell(pb);

	if (!(mflags & 0x40)) {
	/**
	* If 0x40 is not set, the len_off field specifies an offset
	* of this packet's payload data in the complete (reassembled)
	* ASF packet. This is used to spread one ASF packet over
	* multiple RTP packets.
	*/
	if (asf->pktbuf && len_off != avio_tell(asf->pktbuf)) {
	ffio_free_dyn_buf(&asf->pktbuf);
	}
	if (!len_off && !asf->pktbuf &&
	(res = avio_open_dyn_buf(&asf->pktbuf)) < 0)
	return res;
	if (!asf->pktbuf)
	return AVERROR(EIO);

	avio_write(asf->pktbuf, buf + off, len - off);
	avio_skip(pb, len - off);
	if (!(flags & RTP_FLAG_MARKER))
	return -1;
	out_len = avio_close_dyn_buf(asf->pktbuf, &asf->buf);
	asf->pktbuf = NULL;
	} else {
	/**
	* If 0x40 is set, the len_off field specifies the length of
	* the next ASF packet that can be read from this payload
	* data alone. This is commonly the same as the payload size,
	* but could be less in case of packet splitting (i.e.
	* multiple ASF packets in one RTP packet).
	*/

	int cur_len = start_off + len_off - off;
	int prev_len = out_len;
	out_len += cur_len;
	if (FFMIN(cur_len, len - off) < 0)
	return -1;
	if ((res = av_reallocp(&asf->buf, out_len)) < 0)
	return res;
	memcpy(asf->buf + prev_len, buf + off,
	FFMIN(cur_len, len - off));
	avio_skip(pb, cur_len);
	}
	}

	init_packetizer(pb, asf->buf, out_len);
	pb->pos += rt->asf_pb_pos;
	pb->eof_reached = 0;
	rt->asf_ctx->pb = pb;
	}

	for (;;) {
	int i;

	res = ff_read_packet(rt->asf_ctx, pkt);
	rt->asf_pb_pos = avio_tell(pb);
	if (res != 0)
	break;
	for (i = 0; i < s->nb_streams; i++) {
	if (s->streams[i]->id == rt->asf_ctx->streams[pkt->stream_index]->id) {
	pkt->stream_index = i;
	return 1; // FIXME: return 0 if last packet
	}
	}
	av_packet_unref(pkt);
	}

	return res == 1 ? -1 : res;
	}

	static void asfrtp_close_context(PayloadContext *asf)
	{
	ffio_free_dyn_buf(&asf->pktbuf);
	av_freep(&asf->buf);
	}

	#define RTP_ASF_HANDLER(n, s, t) \
	const RTPDynamicProtocolHandler ff_ms_rtp_ ## n ## _handler = { \
	.enc_name = s, \
	.codec_type = t, \
	.codec_id = AV_CODEC_ID_NONE, \
	.priv_data_size = sizeof(PayloadContext), \
	.parse_sdp_a_line = asfrtp_parse_sdp_line, \
	.close = asfrtp_close_context, \
	.parse_packet = asfrtp_parse_packet, \
	}

	RTP_ASF_HANDLER(asf_pfv, "x-asf-pf", AVMEDIA_TYPE_VIDEO);
	RTP_ASF_HANDLER(asf_pfa, "x-asf-pf", AVMEDIA_TYPE_AUDIO);