[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
	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	};