[deb_ffmpeg.git] / ffmpeg / libavformat / rtpdec_vp8.c

/*
 * RTP VP8 Depacketizer
 * Copyright (c) 2010 Josh Allmann
 * Copyright (c) 2012 Martin Storsjo
 *
 * 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 RTP support for the VP8 payload
 * @author Josh Allmann <joshua.allmann@gmail.com>
 * @see http://tools.ietf.org/html/draft-ietf-payload-vp8-05
 */

#include "libavcodec/bytestream.h"

#include "rtpdec_formats.h"

struct PayloadContext {
    AVIOContext *data;
    uint32_t     timestamp;
    int          is_keyframe;
    /* If sequence_ok is set, we keep returning data (even if we might have
     * lost some data, but we haven't lost any too critical data that would
     * cause the decoder to desynchronize and output random garbage).
     */
    int          sequence_ok;
    int          first_part_size;
    uint16_t     prev_seq;
    int          prev_pictureid;
    int          broken_frame;
    /* If sequence_dirty is set, we have lost some data (critical or
     * non-critical) and decoding will have some sort of artefacts, and
     * we thus should request a new keyframe.
     */
    int          sequence_dirty;
    int          got_keyframe;
};

static void vp8_free_buffer(PayloadContext *vp8)
{
    uint8_t *tmp;
    if (!vp8->data)
        return;
    avio_close_dyn_buf(vp8->data, &tmp);
    av_free(tmp);
    vp8->data = NULL;
}

static int vp8_broken_sequence(AVFormatContext *ctx, PayloadContext *vp8,
                               const char *msg)
{
    vp8->sequence_ok = 0;
    av_log(ctx, AV_LOG_WARNING, "%s", msg);
    vp8_free_buffer(vp8);
    return AVERROR(EAGAIN);
}

static int vp8_handle_packet(AVFormatContext *ctx, PayloadContext *vp8,
                             AVStream *st, AVPacket *pkt, uint32_t *timestamp,
                             const uint8_t *buf, int len, uint16_t seq,
                             int flags)
{
    int start_partition, end_packet;
    int extended_bits, part_id;
    int pictureid_present = 0, tl0picidx_present = 0, tid_present = 0,
        keyidx_present = 0;
    int pictureid = -1, pictureid_mask = 0;
    int returned_old_frame = 0;
    uint32_t old_timestamp = 0;

    if (!buf) {
        if (vp8->data) {
            int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
            if (ret < 0)
                return ret;
            *timestamp = vp8->timestamp;
            if (vp8->sequence_dirty)
                pkt->flags |= AV_PKT_FLAG_CORRUPT;
            return 0;
        }
        return AVERROR(EAGAIN);
    }

    if (len < 1)
        return AVERROR_INVALIDDATA;

    extended_bits   = buf[0] & 0x80;
    start_partition = buf[0] & 0x10;
    part_id         = buf[0] & 0x0f;
    end_packet      = flags & RTP_FLAG_MARKER;
    buf++;
    len--;
    if (extended_bits) {
        if (len < 1)
            return AVERROR_INVALIDDATA;
        pictureid_present = buf[0] & 0x80;
        tl0picidx_present = buf[0] & 0x40;
        tid_present       = buf[0] & 0x20;
        keyidx_present    = buf[0] & 0x10;
        buf++;
        len--;
    }
    if (pictureid_present) {
        if (len < 1)
            return AVERROR_INVALIDDATA;
        if (buf[0] & 0x80) {
            if (len < 2)
                return AVERROR_INVALIDDATA;
            pictureid = AV_RB16(buf) & 0x7fff;
            pictureid_mask = 0x7fff;
            buf += 2;
            len -= 2;
        } else {
            pictureid = buf[0] & 0x7f;
            pictureid_mask = 0x7f;
            buf++;
            len--;
        }
    }
    if (tl0picidx_present) {
        // Ignoring temporal level zero index
        buf++;
        len--;
    }
    if (tid_present || keyidx_present) {
        // Ignoring temporal layer index, layer sync bit and keyframe index
        buf++;
        len--;
    }
    if (len < 1)
        return AVERROR_INVALIDDATA;

    if (start_partition && part_id == 0 && len >= 3) {
        int res;
        int non_key = buf[0] & 0x01;
        if (!non_key) {
            vp8_free_buffer(vp8);
            // Keyframe, decoding ok again
            vp8->sequence_ok = 1;
            vp8->sequence_dirty = 0;
            vp8->got_keyframe = 1;
        } else {
            int can_continue = vp8->data && !vp8->is_keyframe &&
                               avio_tell(vp8->data) >= vp8->first_part_size;
            if (!vp8->sequence_ok)
                return AVERROR(EAGAIN);
            if (!vp8->got_keyframe)
                return vp8_broken_sequence(ctx, vp8, "Keyframe missing\n");
            if (pictureid >= 0) {
                if (pictureid != ((vp8->prev_pictureid + 1) & pictureid_mask)) {
                    return vp8_broken_sequence(ctx, vp8,
                                               "Missed a picture, sequence broken\n");
                } else {
                    if (vp8->data && !can_continue)
                        return vp8_broken_sequence(ctx, vp8,
                                                   "Missed a picture, sequence broken\n");
                }
            } else {
                uint16_t expected_seq = vp8->prev_seq + 1;
                int16_t diff = seq - expected_seq;
                if (vp8->data) {
                    // No picture id, so we can't know if missed packets
                    // contained any new frames. If diff == 0, we did get
                    // later packets from the same frame (matching timestamp),
                    // so we know we didn't miss any frame. If diff == 1 and
                    // we still have data (not flushed by the end of frame
                    // marker), the single missed packet must have been part
                    // of the same frame.
                    if ((diff == 0 || diff == 1) && can_continue) {
                        // Proceed with what we have
                    } else {
                        return vp8_broken_sequence(ctx, vp8,
                                                   "Missed too much, sequence broken\n");
                    }
                } else {
                    if (diff != 0)
                        return vp8_broken_sequence(ctx, vp8,
                                                   "Missed unknown data, sequence broken\n");
                }
            }
            if (vp8->data) {
                vp8->sequence_dirty = 1;
                if (avio_tell(vp8->data) >= vp8->first_part_size) {
                    int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
                    if (ret < 0)
                        return ret;
                    pkt->flags |= AV_PKT_FLAG_CORRUPT;
                    returned_old_frame = 1;
                    old_timestamp = vp8->timestamp;
                } else {
                    // Shouldn't happen
                    vp8_free_buffer(vp8);
                }
            }
        }
        vp8->first_part_size = (AV_RL16(&buf[1]) << 3 | buf[0] >> 5) + 3;
        if ((res = avio_open_dyn_buf(&vp8->data)) < 0)
            return res;
        vp8->timestamp = *timestamp;
        vp8->broken_frame = 0;
        vp8->prev_pictureid = pictureid;
        vp8->is_keyframe = !non_key;
    } else {
        uint16_t expected_seq = vp8->prev_seq + 1;

        if (!vp8->sequence_ok)
            return AVERROR(EAGAIN);

        if (vp8->timestamp != *timestamp) {
            // Missed the start of the new frame, sequence broken
            return vp8_broken_sequence(ctx, vp8,
                                       "Received no start marker; dropping frame\n");
        }

        if (seq != expected_seq) {
            if (vp8->is_keyframe) {
                return vp8_broken_sequence(ctx, vp8,
                                           "Missed part of a keyframe, sequence broken\n");
            } else if (vp8->data && avio_tell(vp8->data) >= vp8->first_part_size) {
                vp8->broken_frame = 1;
                vp8->sequence_dirty = 1;
            } else {
                return vp8_broken_sequence(ctx, vp8,
                                           "Missed part of the first partition, sequence broken\n");
            }
        }
    }

    if (!vp8->data)
        return vp8_broken_sequence(ctx, vp8, "Received no start marker\n");

    vp8->prev_seq = seq;
    if (!vp8->broken_frame)
        avio_write(vp8->data, buf, len);

    if (returned_old_frame) {
        *timestamp = old_timestamp;
        return end_packet ? 1 : 0;
    }

    if (end_packet) {
        int ret;
        ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
        if (ret < 0)
            return ret;
        if (vp8->sequence_dirty)
            pkt->flags |= AV_PKT_FLAG_CORRUPT;
        return 0;
    }

    return AVERROR(EAGAIN);
}

static PayloadContext *vp8_new_context(void)
{
    PayloadContext *vp8 = av_mallocz(sizeof(PayloadContext));
    if (!vp8)
        return NULL;
    vp8->sequence_ok = 1;
    return vp8;
}

static void vp8_free_context(PayloadContext *vp8)
{
    vp8_free_buffer(vp8);
    av_free(vp8);
}

static int vp8_need_keyframe(PayloadContext *vp8)
{
    return vp8->sequence_dirty || !vp8->sequence_ok;
}

RTPDynamicProtocolHandler ff_vp8_dynamic_handler = {
    .enc_name       = "VP8",
    .codec_type     = AVMEDIA_TYPE_VIDEO,
    .codec_id       = AV_CODEC_ID_VP8,
    .alloc          = vp8_new_context,
    .free           = vp8_free_context,
    .parse_packet   = vp8_handle_packet,
    .need_keyframe  = vp8_need_keyframe,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* RTP VP8 Depacketizer
	3	* Copyright (c) 2010 Josh Allmann
	4	* Copyright (c) 2012 Martin Storsjo
	5	*
	6	* This file is part of FFmpeg.
	7	*
	8	* FFmpeg is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; either
	11	* version 2.1 of the License, or (at your option) any later version.
	12	*
	13	* FFmpeg is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with FFmpeg; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	/**
	24	* @file
	25	* @brief RTP support for the VP8 payload
	26	* @author Josh Allmann <joshua.allmann@gmail.com>
	27	* @see http://tools.ietf.org/html/draft-ietf-payload-vp8-05
	28	*/
	29
	30	#include "libavcodec/bytestream.h"
	31
	32	#include "rtpdec_formats.h"
	33
	34	struct PayloadContext {
	35	AVIOContext *data;
	36	uint32_t timestamp;
	37	int is_keyframe;
	38	/* If sequence_ok is set, we keep returning data (even if we might have
	39	* lost some data, but we haven't lost any too critical data that would
	40	* cause the decoder to desynchronize and output random garbage).
	41	*/
	42	int sequence_ok;
	43	int first_part_size;
	44	uint16_t prev_seq;
	45	int prev_pictureid;
	46	int broken_frame;
	47	/* If sequence_dirty is set, we have lost some data (critical or
	48	* non-critical) and decoding will have some sort of artefacts, and
	49	* we thus should request a new keyframe.
	50	*/
	51	int sequence_dirty;
	52	int got_keyframe;
	53	};
	54
	55	static void vp8_free_buffer(PayloadContext *vp8)
	56	{
	57	uint8_t *tmp;
	58	if (!vp8->data)
	59	return;
	60	avio_close_dyn_buf(vp8->data, &tmp);
	61	av_free(tmp);
	62	vp8->data = NULL;
	63	}
	64
65	static int vp8_broken_sequence(AVFormatContext ctx, PayloadContext vp8,
66	const char *msg)
67	{
68	vp8->sequence_ok = 0;
69	av_log(ctx, AV_LOG_WARNING, "%s", msg);
70	vp8_free_buffer(vp8);
71	return AVERROR(EAGAIN);
72	}
73
74	static int vp8_handle_packet(AVFormatContext ctx, PayloadContext vp8,
75	AVStream st, AVPacket pkt, uint32_t *timestamp,
76	const uint8_t *buf, int len, uint16_t seq,
77	int flags)
78	{
79	int start_partition, end_packet;
80	int extended_bits, part_id;
81	int pictureid_present = 0, tl0picidx_present = 0, tid_present = 0,
82	keyidx_present = 0;
83	int pictureid = -1, pictureid_mask = 0;
84	int returned_old_frame = 0;
85	uint32_t old_timestamp = 0;
86
87	if (!buf) {
88	if (vp8->data) {
89	int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
90	if (ret < 0)
91	return ret;
92	*timestamp = vp8->timestamp;
93	if (vp8->sequence_dirty)
94	pkt->flags \|= AV_PKT_FLAG_CORRUPT;
95	return 0;
96	}
97	return AVERROR(EAGAIN);
98	}
99
100	if (len < 1)
101	return AVERROR_INVALIDDATA;
102
103	extended_bits = buf[0] & 0x80;
104	start_partition = buf[0] & 0x10;
105	part_id = buf[0] & 0x0f;
106	end_packet = flags & RTP_FLAG_MARKER;
107	buf++;
108	len--;
109	if (extended_bits) {
110	if (len < 1)
111	return AVERROR_INVALIDDATA;
112	pictureid_present = buf[0] & 0x80;
113	tl0picidx_present = buf[0] & 0x40;
114	tid_present = buf[0] & 0x20;
115	keyidx_present = buf[0] & 0x10;
116	buf++;
117	len--;
118	}
119	if (pictureid_present) {
120	if (len < 1)
121	return AVERROR_INVALIDDATA;
122	if (buf[0] & 0x80) {
123	if (len < 2)
124	return AVERROR_INVALIDDATA;
125	pictureid = AV_RB16(buf) & 0x7fff;
126	pictureid_mask = 0x7fff;
127	buf += 2;
128	len -= 2;
129	} else {
130	pictureid = buf[0] & 0x7f;
131	pictureid_mask = 0x7f;
132	buf++;
133	len--;
134	}
135	}
136	if (tl0picidx_present) {
137	// Ignoring temporal level zero index
138	buf++;
139	len--;
140	}
141	if (tid_present \|\| keyidx_present) {
142	// Ignoring temporal layer index, layer sync bit and keyframe index
143	buf++;
144	len--;
145	}
146	if (len < 1)
147	return AVERROR_INVALIDDATA;
148
149	if (start_partition && part_id == 0 && len >= 3) {
150	int res;
151	int non_key = buf[0] & 0x01;
152	if (!non_key) {
153	vp8_free_buffer(vp8);
154	// Keyframe, decoding ok again
155	vp8->sequence_ok = 1;
156	vp8->sequence_dirty = 0;
157	vp8->got_keyframe = 1;
158	} else {
159	int can_continue = vp8->data && !vp8->is_keyframe &&
160	avio_tell(vp8->data) >= vp8->first_part_size;
161	if (!vp8->sequence_ok)
162	return AVERROR(EAGAIN);
163	if (!vp8->got_keyframe)
164	return vp8_broken_sequence(ctx, vp8, "Keyframe missing\n");
165	if (pictureid >= 0) {
166	if (pictureid != ((vp8->prev_pictureid + 1) & pictureid_mask)) {
167	return vp8_broken_sequence(ctx, vp8,
168	"Missed a picture, sequence broken\n");
169	} else {
170	if (vp8->data && !can_continue)
171	return vp8_broken_sequence(ctx, vp8,
172	"Missed a picture, sequence broken\n");
173	}
174	} else {
175	uint16_t expected_seq = vp8->prev_seq + 1;
176	int16_t diff = seq - expected_seq;
177	if (vp8->data) {
178	// No picture id, so we can't know if missed packets
179	// contained any new frames. If diff == 0, we did get
180	// later packets from the same frame (matching timestamp),
181	// so we know we didn't miss any frame. If diff == 1 and
182	// we still have data (not flushed by the end of frame
183	// marker), the single missed packet must have been part
184	// of the same frame.
185	if ((diff == 0 \|\| diff == 1) && can_continue) {
186	// Proceed with what we have
187	} else {
188	return vp8_broken_sequence(ctx, vp8,
189	"Missed too much, sequence broken\n");
190	}
191	} else {
192	if (diff != 0)
193	return vp8_broken_sequence(ctx, vp8,
194	"Missed unknown data, sequence broken\n");
195	}
196	}
197	if (vp8->data) {
198	vp8->sequence_dirty = 1;
199	if (avio_tell(vp8->data) >= vp8->first_part_size) {
200	int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
201	if (ret < 0)
202	return ret;
203	pkt->flags \|= AV_PKT_FLAG_CORRUPT;
204	returned_old_frame = 1;
205	old_timestamp = vp8->timestamp;
206	} else {
207	// Shouldn't happen
208	vp8_free_buffer(vp8);
209	}
210	}
211	}
212	vp8->first_part_size = (AV_RL16(&buf[1]) << 3 \| buf[0] >> 5) + 3;
213	if ((res = avio_open_dyn_buf(&vp8->data)) < 0)
214	return res;
215	vp8->timestamp = *timestamp;
216	vp8->broken_frame = 0;
217	vp8->prev_pictureid = pictureid;
218	vp8->is_keyframe = !non_key;
219	} else {
220	uint16_t expected_seq = vp8->prev_seq + 1;
221
222	if (!vp8->sequence_ok)
223	return AVERROR(EAGAIN);
224
225	if (vp8->timestamp != *timestamp) {
226	// Missed the start of the new frame, sequence broken
227	return vp8_broken_sequence(ctx, vp8,
228	"Received no start marker; dropping frame\n");
229	}
230
231	if (seq != expected_seq) {
232	if (vp8->is_keyframe) {
233	return vp8_broken_sequence(ctx, vp8,
234	"Missed part of a keyframe, sequence broken\n");
235	} else if (vp8->data && avio_tell(vp8->data) >= vp8->first_part_size) {
236	vp8->broken_frame = 1;
237	vp8->sequence_dirty = 1;
238	} else {
239	return vp8_broken_sequence(ctx, vp8,
240	"Missed part of the first partition, sequence broken\n");
241	}
242	}
243	}
244
245	if (!vp8->data)
246	return vp8_broken_sequence(ctx, vp8, "Received no start marker\n");
247
248	vp8->prev_seq = seq;
249	if (!vp8->broken_frame)
250	avio_write(vp8->data, buf, len);
251
252	if (returned_old_frame) {
253	*timestamp = old_timestamp;
254	return end_packet ? 1 : 0;
255	}
256
257	if (end_packet) {
258	int ret;
259	ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
260	if (ret < 0)
261	return ret;
262	if (vp8->sequence_dirty)
263	pkt->flags \|= AV_PKT_FLAG_CORRUPT;
264	return 0;
265	}
266
267	return AVERROR(EAGAIN);
268	}
269
270	static PayloadContext *vp8_new_context(void)
271	{
272	PayloadContext *vp8 = av_mallocz(sizeof(PayloadContext));
273	if (!vp8)
274	return NULL;
275	vp8->sequence_ok = 1;
276	return vp8;
277	}
278
279	static void vp8_free_context(PayloadContext *vp8)
280	{
281	vp8_free_buffer(vp8);
282	av_free(vp8);
283	}
284
285	static int vp8_need_keyframe(PayloadContext *vp8)
286	{
287	return vp8->sequence_dirty \|\| !vp8->sequence_ok;
288	}
289
290	RTPDynamicProtocolHandler ff_vp8_dynamic_handler = {
291	.enc_name = "VP8",
292	.codec_type = AVMEDIA_TYPE_VIDEO,
293	.codec_id = AV_CODEC_ID_VP8,
294	.alloc = vp8_new_context,
295	.free = vp8_free_context,
296	.parse_packet = vp8_handle_packet,
297	.need_keyframe = vp8_need_keyframe,
298	};