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 const AVCodecTag swf_audio_codec_tags[] = {
00027     { AV_CODEC_ID_PCM_S16LE,  0x00 },
00028     { AV_CODEC_ID_ADPCM_SWF,  0x01 },
00029     { AV_CODEC_ID_MP3,        0x02 },
00030     { AV_CODEC_ID_PCM_S16LE,  0x03 },
00031 //  { AV_CODEC_ID_NELLYMOSER, 0x06 },
00032     { AV_CODEC_ID_NONE,          0 },
00033 };
00034 
00035 static int get_swf_tag(AVIOContext *pb, int *len_ptr)
00036 {
00037     int tag, len;
00038 
00039     if (url_feof(pb))
00040         return AVERROR_EOF;
00041 
00042     tag = avio_rl16(pb);
00043     len = tag & 0x3f;
00044     tag = tag >> 6;
00045     if (len == 0x3f) {
00046         len = avio_rl32(pb);
00047     }
00048 //    av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
00049     *len_ptr = len;
00050     return tag;
00051 }
00052 
00053 
00054 static int swf_probe(AVProbeData *p)
00055 {
00056     /* check file header */
00057     if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
00058         p->buf[2] == 'S')
00059         return AVPROBE_SCORE_MAX;
00060     else
00061         return 0;
00062 }
00063 
00064 #if CONFIG_ZLIB
00065 static int zlib_refill(void *opaque, uint8_t *buf, int buf_size)
00066 {
00067     AVFormatContext *s = opaque;
00068     SWFContext *swf = s->priv_data;
00069     z_stream *z = &swf->zstream;
00070     int ret;
00071 
00072 retry:
00073     if (!z->avail_in) {
00074         int n = avio_read(s->pb, swf->zbuf_in, ZBUF_SIZE);
00075         if (n <= 0)
00076             return n;
00077         z->next_in  = swf->zbuf_in;
00078         z->avail_in = n;
00079     }
00080 
00081     z->next_out  = buf;
00082     z->avail_out = buf_size;
00083 
00084     ret = inflate(z, Z_NO_FLUSH);
00085     if (ret < 0)
00086         return AVERROR(EINVAL);
00087     if (ret == Z_STREAM_END)
00088         return AVERROR_EOF;
00089 
00090     if (buf_size - z->avail_out == 0)
00091         goto retry;
00092 
00093     return buf_size - z->avail_out;
00094 }
00095 #endif
00096 
00097 static int swf_read_header(AVFormatContext *s)
00098 {
00099     SWFContext *swf = s->priv_data;
00100     AVIOContext *pb = s->pb;
00101     int nbits, len, tag;
00102 
00103     tag = avio_rb32(pb) & 0xffffff00;
00104     avio_rl32(pb);
00105 
00106     if (tag == MKBETAG('C', 'W', 'S', 0)) {
00107         av_log(s, AV_LOG_INFO, "SWF compressed file detected\n");
00108 #if CONFIG_ZLIB
00109         swf->zbuf_in  = av_malloc(ZBUF_SIZE);
00110         swf->zbuf_out = av_malloc(ZBUF_SIZE);
00111         swf->zpb = avio_alloc_context(swf->zbuf_out, ZBUF_SIZE, 0, s,
00112                                       zlib_refill, NULL, NULL);
00113         if (!swf->zbuf_in || !swf->zbuf_out || !swf->zpb)
00114             return AVERROR(ENOMEM);
00115         swf->zpb->seekable = 0;
00116         if (inflateInit(&swf->zstream) != Z_OK) {
00117             av_log(s, AV_LOG_ERROR, "Unable to init zlib context\n");
00118             return AVERROR(EINVAL);
00119         }
00120         pb = swf->zpb;
00121 #else
00122         av_log(s, AV_LOG_ERROR, "zlib support is required to read SWF compressed files\n");
00123         return AVERROR(EIO);
00124 #endif
00125     } else if (tag != MKBETAG('F', 'W', 'S', 0))
00126         return AVERROR(EIO);
00127     /* skip rectangle size */
00128     nbits = avio_r8(pb) >> 3;
00129     len = (4 * nbits - 3 + 7) / 8;
00130     avio_skip(pb, len);
00131     swf->frame_rate = avio_rl16(pb); /* 8.8 fixed */
00132     avio_rl16(pb); /* frame count */
00133 
00134     swf->samples_per_frame = 0;
00135     s->ctx_flags |= AVFMTCTX_NOHEADER;
00136     return 0;
00137 }
00138 
00139 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
00140 {
00141     SWFContext *swf = s->priv_data;
00142     AVIOContext *pb = s->pb;
00143     AVStream *vst = NULL, *ast = NULL, *st = 0;
00144     int tag, len, i, frame, v, res;
00145 
00146 #if CONFIG_ZLIB
00147     if (swf->zpb)
00148         pb = swf->zpb;
00149 #endif
00150 
00151     for(;;) {
00152         uint64_t pos = avio_tell(pb);
00153         tag = get_swf_tag(pb, &len);
00154         if (tag < 0)
00155             return tag;
00156         if (tag == TAG_VIDEOSTREAM) {
00157             int ch_id = avio_rl16(pb);
00158             len -= 2;
00159 
00160             for (i=0; i<s->nb_streams; i++) {
00161                 st = s->streams[i];
00162                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id)
00163                     goto skip;
00164             }
00165 
00166             avio_rl16(pb);
00167             avio_rl16(pb);
00168             avio_rl16(pb);
00169             avio_r8(pb);
00170             /* Check for FLV1 */
00171             vst = avformat_new_stream(s, NULL);
00172             if (!vst)
00173                 return -1;
00174             vst->id = ch_id;
00175             vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00176             vst->codec->codec_id = ff_codec_get_id(ff_swf_codec_tags, avio_r8(pb));
00177             avpriv_set_pts_info(vst, 16, 256, swf->frame_rate);
00178             len -= 8;
00179         } else if (tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) {
00180             /* streaming found */
00181             int sample_rate_code;
00182 
00183             for (i=0; i<s->nb_streams; i++) {
00184                 st = s->streams[i];
00185                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1)
00186                     goto skip;
00187             }
00188 
00189             avio_r8(pb);
00190             v = avio_r8(pb);
00191             swf->samples_per_frame = avio_rl16(pb);
00192             ast = avformat_new_stream(s, NULL);
00193             if (!ast)
00194                 return -1;
00195             ast->id = -1; /* -1 to avoid clash with video stream ch_id */
00196             ast->codec->channels = 1 + (v&1);
00197             ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00198             ast->codec->codec_id = ff_codec_get_id(swf_audio_codec_tags, (v>>4) & 15);
00199             ast->need_parsing = AVSTREAM_PARSE_FULL;
00200             sample_rate_code= (v>>2) & 3;
00201             ast->codec->sample_rate = 44100 >> (3 - sample_rate_code);
00202             avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
00203             len -= 4;
00204         } else if (tag == TAG_VIDEOFRAME) {
00205             int ch_id = avio_rl16(pb);
00206             len -= 2;
00207             for(i=0; i<s->nb_streams; i++) {
00208                 st = s->streams[i];
00209                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) {
00210                     frame = avio_rl16(pb);
00211                     if ((res = av_get_packet(pb, pkt, len-2)) < 0)
00212                         return res;
00213                     pkt->pos = pos;
00214                     pkt->pts = frame;
00215                     pkt->stream_index = st->index;
00216                     return pkt->size;
00217                 }
00218             }
00219         } else if (tag == TAG_STREAMBLOCK) {
00220             for (i = 0; i < s->nb_streams; i++) {
00221                 st = s->streams[i];
00222                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) {
00223             if (st->codec->codec_id == AV_CODEC_ID_MP3) {
00224                 avio_skip(pb, 4);
00225                 if ((res = av_get_packet(pb, pkt, len-4)) < 0)
00226                     return res;
00227             } else { // ADPCM, PCM
00228                 if ((res = av_get_packet(pb, pkt, len)) < 0)
00229                     return res;
00230             }
00231             pkt->pos = pos;
00232             pkt->stream_index = st->index;
00233             return pkt->size;
00234                 }
00235             }
00236         } else if (tag == TAG_JPEG2) {
00237             for (i=0; i<s->nb_streams; i++) {
00238                 st = s->streams[i];
00239                 if (st->codec->codec_id == AV_CODEC_ID_MJPEG && st->id == -2)
00240                     break;
00241             }
00242             if (i == s->nb_streams) {
00243                 vst = avformat_new_stream(s, NULL);
00244                 if (!vst)
00245                     return -1;
00246                 vst->id = -2; /* -2 to avoid clash with video stream and audio stream */
00247                 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00248                 vst->codec->codec_id = AV_CODEC_ID_MJPEG;
00249                 avpriv_set_pts_info(vst, 64, 256, swf->frame_rate);
00250                 st = vst;
00251             }
00252             avio_rl16(pb); /* BITMAP_ID */
00253             if ((res = av_new_packet(pkt, len-2)) < 0)
00254                 return res;
00255             avio_read(pb, pkt->data, 4);
00256             if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
00257                 AV_RB32(pkt->data) == 0xffd9ffd8) {
00258                 /* old SWF files containing SOI/EOI as data start */
00259                 /* files created by swink have reversed tag */
00260                 pkt->size -= 4;
00261                 avio_read(pb, pkt->data, pkt->size);
00262             } else {
00263                 avio_read(pb, pkt->data + 4, pkt->size - 4);
00264             }
00265             pkt->pos = pos;
00266             pkt->stream_index = st->index;
00267             return pkt->size;
00268         }
00269     skip:
00270         avio_skip(pb, len);
00271     }
00272 }
00273 
00274 #if CONFIG_ZLIB
00275 static av_cold int swf_read_close(AVFormatContext *avctx)
00276 {
00277     SWFContext *s = avctx->priv_data;
00278     inflateEnd(&s->zstream);
00279     av_freep(&s->zbuf_in);
00280     av_freep(&s->zbuf_out);
00281     av_freep(&s->zpb);
00282     return 0;
00283 }
00284 #endif
00285 
00286 AVInputFormat ff_swf_demuxer = {
00287     .name           = "swf",
00288     .long_name      = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
00289     .priv_data_size = sizeof(SWFContext),
00290     .read_probe     = swf_probe,
00291     .read_header    = swf_read_header,
00292     .read_packet    = swf_read_packet,
00293 #if CONFIG_ZLIB
00294     .read_close     = swf_read_close,
00295 #endif
00296 };