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ffmpeg / libavformat / ffmdec.c @ 85a6b01d

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1
/*
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 * FFM (ffserver live feed) demuxer
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 * Copyright (c) 2001 Fabrice Bellard.
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
21

    
22
#include "avformat.h"
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#include "ffm.h"
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#include <unistd.h>
25

    
26
static int64_t get_pts(AVFormatContext *s, offset_t pos);
27

    
28
static int ffm_is_avail_data(AVFormatContext *s, int size)
29
{
30
    FFMContext *ffm = s->priv_data;
31
    offset_t pos, avail_size;
32
    int len;
33

    
34
    len = ffm->packet_end - ffm->packet_ptr;
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    if (size <= len)
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        return 1;
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    pos = url_ftell(s->pb);
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    if (pos == ffm->write_index) {
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        /* exactly at the end of stream */
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        return 0;
41
    } else if (pos < ffm->write_index) {
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        avail_size = ffm->write_index - pos;
43
    } else {
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        avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
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    }
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    avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
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    if (size <= avail_size)
48
        return 1;
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    else
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        return 0;
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}
52

    
53
/* first is true if we read the frame header */
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static int ffm_read_data(AVFormatContext *s,
55
                         uint8_t *buf, int size, int first)
56
{
57
    FFMContext *ffm = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int len, fill_size, size1, frame_offset;
60

    
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    size1 = size;
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    while (size > 0) {
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    redo:
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        len = ffm->packet_end - ffm->packet_ptr;
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        if (len > size)
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            len = size;
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        if (len == 0) {
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            if (url_ftell(pb) == ffm->file_size)
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                url_fseek(pb, ffm->packet_size, SEEK_SET);
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    retry_read:
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            get_be16(pb); /* PACKET_ID */
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            fill_size = get_be16(pb);
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            ffm->pts = get_be64(pb);
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            ffm->first_frame_in_packet = 1;
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            frame_offset = get_be16(pb);
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            get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
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            ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
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            if (ffm->packet_end < ffm->packet)
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                return -1;
80
            /* if first packet or resynchronization packet, we must
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               handle it specifically */
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            if (ffm->first_packet || (frame_offset & 0x8000)) {
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                if (!frame_offset) {
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                    /* This packet has no frame headers in it */
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                    if (url_ftell(pb) >= ffm->packet_size * 3) {
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                        url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
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                        goto retry_read;
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                    }
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                    /* This is bad, we cannot find a valid frame header */
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                    return 0;
91
                }
92
                ffm->first_packet = 0;
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                if ((frame_offset & 0x7ffff) < FFM_HEADER_SIZE)
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                    return -1;
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                ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
96
                if (!first)
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                    break;
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            } else {
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                ffm->packet_ptr = ffm->packet;
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            }
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            goto redo;
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        }
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        memcpy(buf, ffm->packet_ptr, len);
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        buf += len;
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        ffm->packet_ptr += len;
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        size -= len;
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        first = 0;
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    }
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    return size1 - size;
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}
111

    
112

    
113
static void adjust_write_index(AVFormatContext *s)
114
{
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    FFMContext *ffm = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int64_t pts;
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    //offset_t orig_write_index = ffm->write_index;
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    offset_t pos_min, pos_max;
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    int64_t pts_start;
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    offset_t ptr = url_ftell(pb);
122

    
123

    
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    pos_min = 0;
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    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
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    pts_start = get_pts(s, pos_min);
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    pts = get_pts(s, pos_max);
130

    
131
    if (pts - 100000 > pts_start)
132
        goto end;
133

    
134
    ffm->write_index = FFM_PACKET_SIZE;
135

    
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    pts_start = get_pts(s, pos_min);
137

    
138
    pts = get_pts(s, pos_max);
139

    
140
    if (pts - 100000 <= pts_start) {
141
        while (1) {
142
            offset_t newpos;
143
            int64_t newpts;
144

    
145
            newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
146

    
147
            if (newpos == pos_min)
148
                break;
149

    
150
            newpts = get_pts(s, newpos);
151

    
152
            if (newpts - 100000 <= pts) {
153
                pos_max = newpos;
154
                pts = newpts;
155
            } else {
156
                pos_min = newpos;
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            }
158
        }
159
        ffm->write_index += pos_max;
160
    }
161

    
162
    //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
163
    //printf("pts range %0.6f - %0.6f\n", get_pts(s, 0) / 1000000. , get_pts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
164

    
165
 end:
166
    url_fseek(pb, ptr, SEEK_SET);
167
}
168

    
169

    
170
static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
171
{
172
    FFMContext *ffm = s->priv_data;
173
    AVStream *st;
174
    FFMStream *fst;
175
    ByteIOContext *pb = s->pb;
176
    AVCodecContext *codec;
177
    int i, nb_streams;
178
    uint32_t tag;
179

    
180
    /* header */
181
    tag = get_le32(pb);
182
    if (tag != MKTAG('F', 'F', 'M', '1'))
183
        goto fail;
184
    ffm->packet_size = get_be32(pb);
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    if (ffm->packet_size != FFM_PACKET_SIZE)
186
        goto fail;
187
    ffm->write_index = get_be64(pb);
188
    /* get also filesize */
189
    if (!url_is_streamed(pb)) {
190
        ffm->file_size = url_fsize(pb);
191
        adjust_write_index(s);
192
    } else {
193
        ffm->file_size = (UINT64_C(1) << 63) - 1;
194
    }
195

    
196
    nb_streams = get_be32(pb);
197
    get_be32(pb); /* total bitrate */
198
    /* read each stream */
199
    for(i=0;i<nb_streams;i++) {
200
        char rc_eq_buf[128];
201

    
202
        st = av_new_stream(s, 0);
203
        if (!st)
204
            goto fail;
205
        fst = av_mallocz(sizeof(FFMStream));
206
        if (!fst)
207
            goto fail;
208
        s->streams[i] = st;
209

    
210
        av_set_pts_info(st, 64, 1, 1000000);
211

    
212
        st->priv_data = fst;
213

    
214
        codec = st->codec;
215
        /* generic info */
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        codec->codec_id = get_be32(pb);
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        codec->codec_type = get_byte(pb); /* codec_type */
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        codec->bit_rate = get_be32(pb);
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        st->quality = get_be32(pb);
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        codec->flags = get_be32(pb);
221
        codec->flags2 = get_be32(pb);
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        codec->debug = get_be32(pb);
223
        /* specific info */
224
        switch(codec->codec_type) {
225
        case CODEC_TYPE_VIDEO:
226
            codec->time_base.num = get_be32(pb);
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            codec->time_base.den = get_be32(pb);
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            codec->width = get_be16(pb);
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            codec->height = get_be16(pb);
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            codec->gop_size = get_be16(pb);
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            codec->pix_fmt = get_be32(pb);
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            codec->qmin = get_byte(pb);
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            codec->qmax = get_byte(pb);
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            codec->max_qdiff = get_byte(pb);
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            codec->qcompress = get_be16(pb) / 10000.0;
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            codec->qblur = get_be16(pb) / 10000.0;
237
            codec->bit_rate_tolerance = get_be32(pb);
238
            codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
239
            codec->rc_max_rate = get_be32(pb);
240
            codec->rc_min_rate = get_be32(pb);
241
            codec->rc_buffer_size = get_be32(pb);
242
            codec->i_quant_factor = av_int2dbl(get_be64(pb));
243
            codec->b_quant_factor = av_int2dbl(get_be64(pb));
244
            codec->i_quant_offset = av_int2dbl(get_be64(pb));
245
            codec->b_quant_offset = av_int2dbl(get_be64(pb));
246
            codec->dct_algo = get_be32(pb);
247
            codec->strict_std_compliance = get_be32(pb);
248
            codec->max_b_frames = get_be32(pb);
249
            codec->luma_elim_threshold = get_be32(pb);
250
            codec->chroma_elim_threshold = get_be32(pb);
251
            codec->mpeg_quant = get_be32(pb);
252
            codec->intra_dc_precision = get_be32(pb);
253
            codec->me_method = get_be32(pb);
254
            codec->mb_decision = get_be32(pb);
255
            codec->nsse_weight = get_be32(pb);
256
            codec->frame_skip_cmp = get_be32(pb);
257
            codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
258
            codec->codec_tag = get_be32(pb);
259
            break;
260
        case CODEC_TYPE_AUDIO:
261
            codec->sample_rate = get_be32(pb);
262
            codec->channels = get_le16(pb);
263
            codec->frame_size = get_le16(pb);
264
            break;
265
        default:
266
            goto fail;
267
        }
268

    
269
    }
270

    
271
    /* get until end of block reached */
272
    while ((url_ftell(pb) % ffm->packet_size) != 0)
273
        get_byte(pb);
274

    
275
    /* init packet demux */
276
    ffm->packet_ptr = ffm->packet;
277
    ffm->packet_end = ffm->packet;
278
    ffm->frame_offset = 0;
279
    ffm->pts = 0;
280
    ffm->read_state = READ_HEADER;
281
    ffm->first_packet = 1;
282
    return 0;
283
 fail:
284
    for(i=0;i<s->nb_streams;i++) {
285
        st = s->streams[i];
286
        if (st) {
287
            av_freep(&st->priv_data);
288
            av_free(st);
289
        }
290
    }
291
    return -1;
292
}
293

    
294
/* return < 0 if eof */
295
static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
296
{
297
    int size;
298
    FFMContext *ffm = s->priv_data;
299
    int duration;
300

    
301
    switch(ffm->read_state) {
302
    case READ_HEADER:
303
        if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE)) {
304
            return AVERROR(EAGAIN);
305
        }
306
#if 0
307
        printf("pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
308
               url_ftell(s->pb), s->pb.pos, ffm->write_index, ffm->file_size);
309
#endif
310
        if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
311
            FRAME_HEADER_SIZE)
312
            return AVERROR(EAGAIN);
313
#if 0
314
        {
315
            int i;
316
            for(i=0;i<FRAME_HEADER_SIZE;i++)
317
                printf("%02x ", ffm->header[i]);
318
            printf("\n");
319
        }
320
#endif
321
        ffm->read_state = READ_DATA;
322
        /* fall thru */
323
    case READ_DATA:
324
        size = AV_RB24(ffm->header + 2);
325
        if (!ffm_is_avail_data(s, size)) {
326
            return AVERROR(EAGAIN);
327
        }
328

    
329
        duration = AV_RB24(ffm->header + 5);
330

    
331
        av_new_packet(pkt, size);
332
        pkt->stream_index = ffm->header[0];
333
        if ((unsigned)pkt->stream_index >= s->nb_streams) {
334
            av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
335
            av_free_packet(pkt);
336
            ffm->read_state = READ_HEADER;
337
            return AVERROR(EAGAIN);
338
        }
339
        pkt->pos = url_ftell(s->pb);
340
        if (ffm->header[1] & FLAG_KEY_FRAME)
341
            pkt->flags |= PKT_FLAG_KEY;
342

    
343
        ffm->read_state = READ_HEADER;
344
        if (ffm_read_data(s, pkt->data, size, 0) != size) {
345
            /* bad case: desynchronized packet. we cancel all the packet loading */
346
            av_free_packet(pkt);
347
            return AVERROR(EAGAIN);
348
        }
349
        if (ffm->first_frame_in_packet)
350
        {
351
            pkt->pts = ffm->pts;
352
            ffm->first_frame_in_packet = 0;
353
        }
354
        pkt->duration = duration;
355
        break;
356
    }
357
    return 0;
358
}
359

    
360
//#define DEBUG_SEEK
361

    
362
/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
363
   by the write position inside this function */
364
static void ffm_seek1(AVFormatContext *s, offset_t pos1)
365
{
366
    FFMContext *ffm = s->priv_data;
367
    ByteIOContext *pb = s->pb;
368
    offset_t pos;
369

    
370
    pos = pos1 + ffm->write_index;
371
    if (pos >= ffm->file_size)
372
        pos -= (ffm->file_size - FFM_PACKET_SIZE);
373
#ifdef DEBUG_SEEK
374
    printf("seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
375
#endif
376
    url_fseek(pb, pos, SEEK_SET);
377
}
378

    
379
static int64_t get_pts(AVFormatContext *s, offset_t pos)
380
{
381
    ByteIOContext *pb = s->pb;
382
    int64_t pts;
383

    
384
    ffm_seek1(s, pos);
385
    url_fskip(pb, 4);
386
    pts = get_be64(pb);
387
#ifdef DEBUG_SEEK
388
    printf("pts=%0.6f\n", pts / 1000000.0);
389
#endif
390
    return pts;
391
}
392

    
393
/* seek to a given time in the file. The file read pointer is
394
   positioned at or before pts. XXX: the following code is quite
395
   approximative */
396
static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
397
{
398
    FFMContext *ffm = s->priv_data;
399
    offset_t pos_min, pos_max, pos;
400
    int64_t pts_min, pts_max, pts;
401
    double pos1;
402

    
403
#ifdef DEBUG_SEEK
404
    printf("wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
405
#endif
406
    /* find the position using linear interpolation (better than
407
       dichotomy in typical cases) */
408
    pos_min = 0;
409
    pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
410
    while (pos_min <= pos_max) {
411
        pts_min = get_pts(s, pos_min);
412
        pts_max = get_pts(s, pos_max);
413
        /* linear interpolation */
414
        pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
415
            (double)(pts_max - pts_min);
416
        pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
417
        if (pos <= pos_min)
418
            pos = pos_min;
419
        else if (pos >= pos_max)
420
            pos = pos_max;
421
        pts = get_pts(s, pos);
422
        /* check if we are lucky */
423
        if (pts == wanted_pts) {
424
            goto found;
425
        } else if (pts > wanted_pts) {
426
            pos_max = pos - FFM_PACKET_SIZE;
427
        } else {
428
            pos_min = pos + FFM_PACKET_SIZE;
429
        }
430
    }
431
    pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
432
    if (pos > 0)
433
        pos -= FFM_PACKET_SIZE;
434
 found:
435
    ffm_seek1(s, pos);
436
    return 0;
437
}
438

    
439
#ifdef CONFIG_FFSERVER
440
offset_t ffm_read_write_index(int fd)
441
{
442
    uint8_t buf[8];
443

    
444
    lseek(fd, 8, SEEK_SET);
445
    read(fd, buf, 8);
446
    return AV_RB64(buf);
447
}
448

    
449
void ffm_write_write_index(int fd, offset_t pos)
450
{
451
    uint8_t buf[8];
452
    int i;
453

    
454
    for(i=0;i<8;i++)
455
        buf[i] = (pos >> (56 - i * 8)) & 0xff;
456
    lseek(fd, 8, SEEK_SET);
457
    write(fd, buf, 8);
458
}
459

    
460
void ffm_set_write_index(AVFormatContext *s, offset_t pos, offset_t file_size)
461
{
462
    FFMContext *ffm = s->priv_data;
463
    ffm->write_index = pos;
464
    ffm->file_size = file_size;
465
}
466
#endif // CONFIG_FFSERVER
467

    
468
static int ffm_read_close(AVFormatContext *s)
469
{
470
    AVStream *st;
471
    int i;
472

    
473
    for(i=0;i<s->nb_streams;i++) {
474
        st = s->streams[i];
475
        av_freep(&st->priv_data);
476
    }
477
    return 0;
478
}
479

    
480
static int ffm_probe(AVProbeData *p)
481
{
482
    if (
483
        p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
484
        p->buf[3] == '1')
485
        return AVPROBE_SCORE_MAX + 1;
486
    return 0;
487
}
488

    
489
AVInputFormat ffm_demuxer = {
490
    "ffm",
491
    "ffm format",
492
    sizeof(FFMContext),
493
    ffm_probe,
494
    ffm_read_header,
495
    ffm_read_packet,
496
    ffm_read_close,
497
    ffm_seek,
498
};