[deb_ffmpeg.git] / ffmpeg / libavformat / rtpdec_h263_rfc2190.c

/*
 * RTP H.263 Depacketizer, RFC 2190
 * Copyright (c) 2012 Martin Storsjo
 * Based on the GStreamer H.263 Depayloder:
 * Copyright 2005 Wim Taymans
 * Copyright 2007 Edward Hervey
 * Copyright 2007 Nokia Corporation
 * Copyright 2007 Collabora Ltd, Philippe Kalaf
 * Copyright 2010 Mark Nauwelaerts
 *
 * 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 "rtpdec_formats.h"
#include "libavutil/attributes.h"
#include "libavutil/intreadwrite.h"
#include "libavcodec/get_bits.h"

struct PayloadContext {
    AVIOContext *buf;
    uint8_t      endbyte;
    int          endbyte_bits;
    uint32_t     timestamp;
    int          newformat;
};

static PayloadContext *h263_new_context(void)
{
    return av_mallocz(sizeof(PayloadContext));
}

static void h263_free_context(PayloadContext *data)
{
    if (!data)
        return;
    if (data->buf) {
        uint8_t *p;
        avio_close_dyn_buf(data->buf, &p);
        av_free(p);
    }
    av_free(data);
}

static av_cold int h263_init(AVFormatContext *ctx, int st_index, PayloadContext *data)
{
    if (st_index < 0)
        return 0;
    ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
    return 0;
}

static int h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
                              const uint8_t *buf, int len, uint16_t seq,
                              int flags)
{
    /* Corresponding to header fields in the RFC */
    int f, p, i, sbit, ebit, src, r;
    int header_size, ret;

    if (data->newformat)
        return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, len,
                                     seq, flags);

    if (data->buf && data->timestamp != *timestamp) {
        /* Dropping old buffered, unfinished data */
        uint8_t *p;
        avio_close_dyn_buf(data->buf, &p);
        av_free(p);
        data->buf = NULL;
    }

    if (len < 4) {
        av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet: %d\n", len);
        return AVERROR_INVALIDDATA;
    }

    f = buf[0] & 0x80;
    p = buf[0] & 0x40;
    if (!f) {
        /* Mode A */
        header_size = 4;
        i = buf[1] & 0x10;
        r = ((buf[1] & 0x01) << 3) | ((buf[2] & 0xe0) >> 5);
    } else if (!p) {
        /* Mode B */
        header_size = 8;
        if (len < header_size) {
            av_log(ctx, AV_LOG_ERROR,
                   "Too short H.263 RTP packet: %d bytes, %d header bytes\n",
                   len, header_size);
            return AVERROR_INVALIDDATA;
        }
        r = buf[3] & 0x03;
        i = buf[4] & 0x80;
    } else {
        /* Mode C */
        header_size = 12;
        if (len < header_size) {
            av_log(ctx, AV_LOG_ERROR,
                   "Too short H.263 RTP packet: %d bytes, %d header bytes\n",
                   len, header_size);
            return AVERROR_INVALIDDATA;
        }
        r = buf[3] & 0x03;
        i = buf[4] & 0x80;
    }
    sbit = (buf[0] >> 3) & 0x7;
    ebit =  buf[0]       & 0x7;
    src  = (buf[1] & 0xe0) >> 5;
    if (!(buf[0] & 0xf8)) { /* Reserved bits in RFC 2429/4629 are zero */
        if ((src == 0 || src >= 6) && r) {
            /* Invalid src for this format, and bits that should be zero
             * according to RFC 2190 aren't zero. */
            av_log(ctx, AV_LOG_WARNING,
                   "Interpreting H263 RTP data as RFC 2429/4629 even though "
                   "signalled with a static payload type.\n");
            data->newformat = 1;
            return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf,
                                         len, seq, flags);
        }
    }

    buf += header_size;
    len -= header_size;

    if (!data->buf) {
        /* Check the picture start code, only start buffering a new frame
         * if this is correct */
        if (len > 4 && AV_RB32(buf) >> 10 == 0x20) {
            ret = avio_open_dyn_buf(&data->buf);
            if (ret < 0)
                return ret;
            data->timestamp = *timestamp;
        } else {
            /* Frame not started yet, skipping */
            return AVERROR(EAGAIN);
        }
    }

    if (data->endbyte_bits || sbit) {
        if (data->endbyte_bits == sbit) {
            data->endbyte |= buf[0] & (0xff >> sbit);
            data->endbyte_bits = 0;
            buf++;
            len--;
            avio_w8(data->buf, data->endbyte);
        } else {
            /* Start/end skip bits not matching - missed packets? */
            GetBitContext gb;
            init_get_bits(&gb, buf, len*8 - ebit);
            skip_bits(&gb, sbit);
            if (data->endbyte_bits) {
                data->endbyte |= get_bits(&gb, 8 - data->endbyte_bits);
                avio_w8(data->buf, data->endbyte);
            }
            while (get_bits_left(&gb) >= 8)
                avio_w8(data->buf, get_bits(&gb, 8));
            data->endbyte_bits = get_bits_left(&gb);
            if (data->endbyte_bits)
                data->endbyte = get_bits(&gb, data->endbyte_bits) <<
                                (8 - data->endbyte_bits);
            ebit = 0;
            len = 0;
        }
    }
    if (ebit) {
        if (len > 0)
            avio_write(data->buf, buf, len - 1);
        data->endbyte_bits = 8 - ebit;
        data->endbyte = buf[len - 1] & (0xff << ebit);
    } else {
        avio_write(data->buf, buf, len);
    }

    if (!(flags & RTP_FLAG_MARKER))
        return AVERROR(EAGAIN);

    if (data->endbyte_bits)
        avio_w8(data->buf, data->endbyte);
    data->endbyte_bits = 0;

    ret = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
    if (ret < 0)
        return ret;
    if (!i)
        pkt->flags   |= AV_PKT_FLAG_KEY;

    return 0;
}

RTPDynamicProtocolHandler ff_h263_rfc2190_dynamic_handler = {
    .codec_type        = AVMEDIA_TYPE_VIDEO,
    .codec_id          = AV_CODEC_ID_H263,
    .init              = h263_init,
    .parse_packet      = h263_handle_packet,
    .alloc             = h263_new_context,
    .free              = h263_free_context,
    .static_payload_id = 34,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* RTP H.263 Depacketizer, RFC 2190
	3	* Copyright (c) 2012 Martin Storsjo
	4	* Based on the GStreamer H.263 Depayloder:
	5	* Copyright 2005 Wim Taymans
	6	* Copyright 2007 Edward Hervey
	7	* Copyright 2007 Nokia Corporation
	8	* Copyright 2007 Collabora Ltd, Philippe Kalaf
	9	* Copyright 2010 Mark Nauwelaerts
	10	*
	11	* This file is part of FFmpeg.
	12	*
	13	* FFmpeg is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU Lesser General Public
	15	* License as published by the Free Software Foundation; either
	16	* version 2.1 of the License, or (at your option) any later version.
	17	*
	18	* FFmpeg is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	21	* Lesser General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU Lesser General Public
	24	* License along with FFmpeg; if not, write to the Free Software
	25	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	26	*/
	27
	28	#include "avformat.h"
	29	#include "rtpdec_formats.h"
	30	#include "libavutil/attributes.h"
	31	#include "libavutil/intreadwrite.h"
	32	#include "libavcodec/get_bits.h"
	33
	34	struct PayloadContext {
	35	AVIOContext *buf;
	36	uint8_t endbyte;
	37	int endbyte_bits;
	38	uint32_t timestamp;
	39	int newformat;
	40	};
	41
	42	static PayloadContext *h263_new_context(void)
	43	{
	44	return av_mallocz(sizeof(PayloadContext));
	45	}
	46
	47	static void h263_free_context(PayloadContext *data)
	48	{
	49	if (!data)
	50	return;
	51	if (data->buf) {
	52	uint8_t *p;
	53	avio_close_dyn_buf(data->buf, &p);
	54	av_free(p);
	55	}
	56	av_free(data);
	57	}
	58
	59	static av_cold int h263_init(AVFormatContext ctx, int st_index, PayloadContext data)
	60	{
	61	if (st_index < 0)
	62	return 0;
	63	ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
	64	return 0;
65	}
66
67	static int h263_handle_packet(AVFormatContext ctx, PayloadContext data,
68	AVStream st, AVPacket pkt, uint32_t *timestamp,
69	const uint8_t *buf, int len, uint16_t seq,
70	int flags)
71	{
72	/* Corresponding to header fields in the RFC */
73	int f, p, i, sbit, ebit, src, r;
74	int header_size, ret;
75
76	if (data->newformat)
77	return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf, len,
78	seq, flags);
79
80	if (data->buf && data->timestamp != *timestamp) {
81	/* Dropping old buffered, unfinished data */
82	uint8_t *p;
83	avio_close_dyn_buf(data->buf, &p);
84	av_free(p);
85	data->buf = NULL;
86	}
87
88	if (len < 4) {
89	av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet: %d\n", len);
90	return AVERROR_INVALIDDATA;
91	}
92
93	f = buf[0] & 0x80;
94	p = buf[0] & 0x40;
95	if (!f) {
96	/* Mode A */
97	header_size = 4;
98	i = buf[1] & 0x10;
99	r = ((buf[1] & 0x01) << 3) \| ((buf[2] & 0xe0) >> 5);
100	} else if (!p) {
101	/* Mode B */
102	header_size = 8;
103	if (len < header_size) {
104	av_log(ctx, AV_LOG_ERROR,
105	"Too short H.263 RTP packet: %d bytes, %d header bytes\n",
106	len, header_size);
107	return AVERROR_INVALIDDATA;
108	}
109	r = buf[3] & 0x03;
110	i = buf[4] & 0x80;
111	} else {
112	/* Mode C */
113	header_size = 12;
114	if (len < header_size) {
115	av_log(ctx, AV_LOG_ERROR,
116	"Too short H.263 RTP packet: %d bytes, %d header bytes\n",
117	len, header_size);
118	return AVERROR_INVALIDDATA;
119	}
120	r = buf[3] & 0x03;
121	i = buf[4] & 0x80;
122	}
123	sbit = (buf[0] >> 3) & 0x7;
124	ebit = buf[0] & 0x7;
125	src = (buf[1] & 0xe0) >> 5;
126	if (!(buf[0] & 0xf8)) { /* Reserved bits in RFC 2429/4629 are zero */
127	if ((src == 0 \|\| src >= 6) && r) {
128	/* Invalid src for this format, and bits that should be zero
129	* according to RFC 2190 aren't zero. */
130	av_log(ctx, AV_LOG_WARNING,
131	"Interpreting H263 RTP data as RFC 2429/4629 even though "
132	"signalled with a static payload type.\n");
133	data->newformat = 1;
134	return ff_h263_handle_packet(ctx, data, st, pkt, timestamp, buf,
135	len, seq, flags);
136	}
137	}
138
139	buf += header_size;
140	len -= header_size;
141
142	if (!data->buf) {
143	/* Check the picture start code, only start buffering a new frame
144	* if this is correct */
145	if (len > 4 && AV_RB32(buf) >> 10 == 0x20) {
146	ret = avio_open_dyn_buf(&data->buf);
147	if (ret < 0)
148	return ret;
149	data->timestamp = *timestamp;
150	} else {
151	/* Frame not started yet, skipping */
152	return AVERROR(EAGAIN);
153	}
154	}
155
156	if (data->endbyte_bits \|\| sbit) {
157	if (data->endbyte_bits == sbit) {
158	data->endbyte \|= buf[0] & (0xff >> sbit);
159	data->endbyte_bits = 0;
160	buf++;
161	len--;
162	avio_w8(data->buf, data->endbyte);
163	} else {
164	/* Start/end skip bits not matching - missed packets? */
165	GetBitContext gb;
166	init_get_bits(&gb, buf, len*8 - ebit);
167	skip_bits(&gb, sbit);
168	if (data->endbyte_bits) {
169	data->endbyte \|= get_bits(&gb, 8 - data->endbyte_bits);
170	avio_w8(data->buf, data->endbyte);
171	}
172	while (get_bits_left(&gb) >= 8)
173	avio_w8(data->buf, get_bits(&gb, 8));
174	data->endbyte_bits = get_bits_left(&gb);
175	if (data->endbyte_bits)
176	data->endbyte = get_bits(&gb, data->endbyte_bits) <<
177	(8 - data->endbyte_bits);
178	ebit = 0;
179	len = 0;
180	}
181	}
182	if (ebit) {
183	if (len > 0)
184	avio_write(data->buf, buf, len - 1);
185	data->endbyte_bits = 8 - ebit;
186	data->endbyte = buf[len - 1] & (0xff << ebit);
187	} else {
188	avio_write(data->buf, buf, len);
189	}
190
191	if (!(flags & RTP_FLAG_MARKER))
192	return AVERROR(EAGAIN);
193
194	if (data->endbyte_bits)
195	avio_w8(data->buf, data->endbyte);
196	data->endbyte_bits = 0;
197
198	ret = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
199	if (ret < 0)
200	return ret;
201	if (!i)
202	pkt->flags \|= AV_PKT_FLAG_KEY;
203
204	return 0;
205	}
206
207	RTPDynamicProtocolHandler ff_h263_rfc2190_dynamic_handler = {
208	.codec_type = AVMEDIA_TYPE_VIDEO,
209	.codec_id = AV_CODEC_ID_H263,
210	.init = h263_init,
211	.parse_packet = h263_handle_packet,
212	.alloc = h263_new_context,
213	.free = h263_free_context,
214	.static_payload_id = 34,
215	};