FFmpeg: libavformat/swfdec.c Source File

00001 /*
00002  * Flash Compatible Streaming Format demuxer
00003  * Copyright (c) 2000 Fabrice Bellard
00004  * Copyright (c) 2003 Tinic Uro
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavutil/intreadwrite.h"
00024 #include "swf.h"
00025 
00026 static int get_swf_tag(AVIOContext *pb, int *len_ptr)
00027 {
00028     int tag, len;
00029 
00030     if (url_feof(pb))
00031         return AVERROR_EOF;
00032 
00033     tag = avio_rl16(pb);
00034     len = tag & 0x3f;
00035     tag = tag >> 6;
00036     if (len == 0x3f) {
00037         len = avio_rl32(pb);
00038     }
00039 //    av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
00040     *len_ptr = len;
00041     return tag;
00042 }
00043 
00044 
00045 static int swf_probe(AVProbeData *p)
00046 {
00047     /* check file header */
00048     if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
00049         p->buf[2] == 'S')
00050         return AVPROBE_SCORE_MAX;
00051     else
00052         return 0;
00053 }
00054 
00055 #if CONFIG_ZLIB
00056 static int zlib_refill(void *opaque, uint8_t *buf, int buf_size)
00057 {
00058     AVFormatContext *s = opaque;
00059     SWFContext *swf = s->priv_data;
00060     z_stream *z = &swf->zstream;
00061     int ret;
00062 
00063 retry:
00064     if (!z->avail_in) {
00065         int n = avio_read(s->pb, swf->zbuf_in, ZBUF_SIZE);
00066         if (n <= 0)
00067             return n;
00068         z->next_in  = swf->zbuf_in;
00069         z->avail_in = n;
00070     }
00071 
00072     z->next_out  = buf;
00073     z->avail_out = buf_size;
00074 
00075     ret = inflate(z, Z_NO_FLUSH);
00076     if (ret < 0)
00077         return AVERROR(EINVAL);
00078     if (ret == Z_STREAM_END)
00079         return AVERROR_EOF;
00080 
00081     if (buf_size - z->avail_out == 0)
00082         goto retry;
00083 
00084     return buf_size - z->avail_out;
00085 }
00086 #endif
00087 
00088 static int swf_read_header(AVFormatContext *s)
00089 {
00090     SWFContext *swf = s->priv_data;
00091     AVIOContext *pb = s->pb;
00092     int nbits, len, tag;
00093 
00094     tag = avio_rb32(pb) & 0xffffff00;
00095     avio_rl32(pb);
00096 
00097     if (tag == MKBETAG('C', 'W', 'S', 0)) {
00098         av_log(s, AV_LOG_INFO, "SWF compressed file detected\n");
00099 #if CONFIG_ZLIB
00100         swf->zbuf_in  = av_malloc(ZBUF_SIZE);
00101         swf->zbuf_out = av_malloc(ZBUF_SIZE);
00102         swf->zpb = avio_alloc_context(swf->zbuf_out, ZBUF_SIZE, 0, s,
00103                                       zlib_refill, NULL, NULL);
00104         if (!swf->zbuf_in || !swf->zbuf_out || !swf->zpb)
00105             return AVERROR(ENOMEM);
00106         swf->zpb->seekable = 0;
00107         if (inflateInit(&swf->zstream) != Z_OK) {
00108             av_log(s, AV_LOG_ERROR, "Unable to init zlib context\n");
00109             return AVERROR(EINVAL);
00110         }
00111         pb = swf->zpb;
00112 #else
00113         av_log(s, AV_LOG_ERROR, "zlib support is required to read SWF compressed files\n");
00114         return AVERROR(EIO);
00115 #endif
00116     } else if (tag != MKBETAG('F', 'W', 'S', 0))
00117         return AVERROR(EIO);
00118     /* skip rectangle size */
00119     nbits = avio_r8(pb) >> 3;
00120     len = (4 * nbits - 3 + 7) / 8;
00121     avio_skip(pb, len);
00122     swf->frame_rate = avio_rl16(pb); /* 8.8 fixed */
00123     avio_rl16(pb); /* frame count */
00124 
00125     swf->samples_per_frame = 0;
00126     s->ctx_flags |= AVFMTCTX_NOHEADER;
00127     return 0;
00128 }
00129 
00130 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
00131 {
00132     SWFContext *swf = s->priv_data;
00133     AVIOContext *pb = s->pb;
00134     AVStream *vst = NULL, *ast = NULL, *st = 0;
00135     int tag, len, i, frame, v, res;
00136 
00137 #if CONFIG_ZLIB
00138     if (swf->zpb)
00139         pb = swf->zpb;
00140 #endif
00141 
00142     for(;;) {
00143         uint64_t pos = avio_tell(pb);
00144         tag = get_swf_tag(pb, &len);
00145         if (tag < 0)
00146             return tag;
00147         if (tag == TAG_VIDEOSTREAM) {
00148             int ch_id = avio_rl16(pb);
00149             len -= 2;
00150 
00151             for (i=0; i<s->nb_streams; i++) {
00152                 st = s->streams[i];
00153                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id)
00154                     goto skip;
00155             }
00156 
00157             avio_rl16(pb);
00158             avio_rl16(pb);
00159             avio_rl16(pb);
00160             avio_r8(pb);
00161             /* Check for FLV1 */
00162             vst = avformat_new_stream(s, NULL);
00163             if (!vst)
00164                 return -1;
00165             vst->id = ch_id;
00166             vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00167             vst->codec->codec_id = ff_codec_get_id(swf_codec_tags, avio_r8(pb));
00168             avpriv_set_pts_info(vst, 16, 256, swf->frame_rate);
00169             len -= 8;
00170         } else if (tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) {
00171             /* streaming found */
00172             int sample_rate_code;
00173 
00174             for (i=0; i<s->nb_streams; i++) {
00175                 st = s->streams[i];
00176                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1)
00177                     goto skip;
00178             }
00179 
00180             avio_r8(pb);
00181             v = avio_r8(pb);
00182             swf->samples_per_frame = avio_rl16(pb);
00183             ast = avformat_new_stream(s, NULL);
00184             if (!ast)
00185                 return -1;
00186             ast->id = -1; /* -1 to avoid clash with video stream ch_id */
00187             ast->codec->channels = 1 + (v&1);
00188             ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00189             ast->codec->codec_id = ff_codec_get_id(swf_audio_codec_tags, (v>>4) & 15);
00190             ast->need_parsing = AVSTREAM_PARSE_FULL;
00191             sample_rate_code= (v>>2) & 3;
00192             ast->codec->sample_rate = 44100 >> (3 - sample_rate_code);
00193             avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
00194             len -= 4;
00195         } else if (tag == TAG_VIDEOFRAME) {
00196             int ch_id = avio_rl16(pb);
00197             len -= 2;
00198             for(i=0; i<s->nb_streams; i++) {
00199                 st = s->streams[i];
00200                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) {
00201                     frame = avio_rl16(pb);
00202                     if ((res = av_get_packet(pb, pkt, len-2)) < 0)
00203                         return res;
00204                     pkt->pos = pos;
00205                     pkt->pts = frame;
00206                     pkt->stream_index = st->index;
00207                     return pkt->size;
00208                 }
00209             }
00210         } else if (tag == TAG_STREAMBLOCK) {
00211             for (i = 0; i < s->nb_streams; i++) {
00212                 st = s->streams[i];
00213                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) {
00214             if (st->codec->codec_id == CODEC_ID_MP3) {
00215                 avio_skip(pb, 4);
00216                 if ((res = av_get_packet(pb, pkt, len-4)) < 0)
00217                     return res;
00218             } else { // ADPCM, PCM
00219                 if ((res = av_get_packet(pb, pkt, len)) < 0)
00220                     return res;
00221             }
00222             pkt->pos = pos;
00223             pkt->stream_index = st->index;
00224             return pkt->size;
00225                 }
00226             }
00227         } else if (tag == TAG_JPEG2) {
00228             for (i=0; i<s->nb_streams; i++) {
00229                 st = s->streams[i];
00230                 if (st->codec->codec_id == CODEC_ID_MJPEG && st->id == -2)
00231                     break;
00232             }
00233             if (i == s->nb_streams) {
00234                 vst = avformat_new_stream(s, NULL);
00235                 if (!vst)
00236                     return -1;
00237                 vst->id = -2; /* -2 to avoid clash with video stream and audio stream */
00238                 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00239                 vst->codec->codec_id = CODEC_ID_MJPEG;
00240                 avpriv_set_pts_info(vst, 64, 256, swf->frame_rate);
00241                 st = vst;
00242             }
00243             avio_rl16(pb); /* BITMAP_ID */
00244             if ((res = av_new_packet(pkt, len-2)) < 0)
00245                 return res;
00246             avio_read(pb, pkt->data, 4);
00247             if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
00248                 AV_RB32(pkt->data) == 0xffd9ffd8) {
00249                 /* old SWF files containing SOI/EOI as data start */
00250                 /* files created by swink have reversed tag */
00251                 pkt->size -= 4;
00252                 avio_read(pb, pkt->data, pkt->size);
00253             } else {
00254                 avio_read(pb, pkt->data + 4, pkt->size - 4);
00255             }
00256             pkt->pos = pos;
00257             pkt->stream_index = st->index;
00258             return pkt->size;
00259         }
00260     skip:
00261         avio_skip(pb, len);
00262     }
00263 }
00264 
00265 #if CONFIG_ZLIB
00266 static av_cold int swf_read_close(AVFormatContext *avctx)
00267 {
00268     SWFContext *s = avctx->priv_data;
00269     inflateEnd(&s->zstream);
00270     av_freep(&s->zbuf_in);
00271     av_freep(&s->zbuf_out);
00272     av_freep(&s->zpb);
00273     return 0;
00274 }
00275 #endif
00276 
00277 AVInputFormat ff_swf_demuxer = {
00278     .name           = "swf",
00279     .long_name      = NULL_IF_CONFIG_SMALL("Flash format"),
00280     .priv_data_size = sizeof(SWFContext),
00281     .read_probe     = swf_probe,
00282     .read_header    = swf_read_header,
00283     .read_packet    = swf_read_packet,
00284 #if CONFIG_ZLIB
00285     .read_close     = swf_read_close,
00286 #endif
00287 };