FFmpeg: libavformat/flacdec.c Source File

00001 /*
00002  * Raw FLAC demuxer
00003  * Copyright (c) 2001 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavcodec/flac.h"
00023 #include "avformat.h"
00024 #include "id3v2.h"
00025 #include "internal.h"
00026 #include "rawdec.h"
00027 #include "oggdec.h"
00028 #include "vorbiscomment.h"
00029 #include "libavcodec/bytestream.h"
00030 
00031 #define RETURN_ERROR(code) do { ret = (code); goto fail; } while (0)
00032 
00033 static int parse_picture(AVFormatContext *s, uint8_t *buf, int buf_size)
00034 {
00035     const CodecMime *mime = ff_id3v2_mime_tags;
00036     enum  AVCodecID      id = AV_CODEC_ID_NONE;
00037     uint8_t mimetype[64], *desc = NULL, *data = NULL;
00038     AVIOContext *pb = NULL;
00039     AVStream *st;
00040     int type, width, height;
00041     int len, ret = 0;
00042 
00043     pb = avio_alloc_context(buf, buf_size, 0, NULL, NULL, NULL, NULL);
00044     if (!pb)
00045         return AVERROR(ENOMEM);
00046 
00047     /* read the picture type */
00048     type      = avio_rb32(pb);
00049     if (type >= FF_ARRAY_ELEMS(ff_id3v2_picture_types) || type < 0) {
00050         av_log(s, AV_LOG_ERROR, "Invalid picture type: %d.\n", type);
00051         if (s->error_recognition & AV_EF_EXPLODE) {
00052             RETURN_ERROR(AVERROR_INVALIDDATA);
00053         }
00054         type = 0;
00055     }
00056 
00057     /* picture mimetype */
00058     len  = avio_rb32(pb);
00059     if (len <= 0 ||
00060         avio_read(pb, mimetype, FFMIN(len, sizeof(mimetype) - 1)) != len) {
00061         av_log(s, AV_LOG_ERROR, "Could not read mimetype from an attached "
00062                "picture.\n");
00063         if (s->error_recognition & AV_EF_EXPLODE)
00064             ret = AVERROR_INVALIDDATA;
00065         goto fail;
00066     }
00067     mimetype[len] = 0;
00068 
00069     while (mime->id != AV_CODEC_ID_NONE) {
00070         if (!strncmp(mime->str, mimetype, sizeof(mimetype))) {
00071             id = mime->id;
00072             break;
00073         }
00074         mime++;
00075     }
00076     if (id == AV_CODEC_ID_NONE) {
00077         av_log(s, AV_LOG_ERROR, "Unknown attached picture mimetype: %s.\n",
00078                mimetype);
00079         if (s->error_recognition & AV_EF_EXPLODE)
00080             ret = AVERROR_INVALIDDATA;
00081         goto fail;
00082     }
00083 
00084     /* picture description */
00085     len = avio_rb32(pb);
00086     if (len > 0) {
00087         if (!(desc = av_malloc(len + 1))) {
00088             RETURN_ERROR(AVERROR(ENOMEM));
00089         }
00090 
00091         if (avio_read(pb, desc, len) != len) {
00092             av_log(s, AV_LOG_ERROR, "Error reading attached picture description.\n");
00093             if (s->error_recognition & AV_EF_EXPLODE)
00094                 ret = AVERROR(EIO);
00095             goto fail;
00096         }
00097         desc[len] = 0;
00098     }
00099 
00100     /* picture metadata */
00101     width  = avio_rb32(pb);
00102     height = avio_rb32(pb);
00103     avio_skip(pb, 8);
00104 
00105     /* picture data */
00106     len = avio_rb32(pb);
00107     if (len <= 0) {
00108         av_log(s, AV_LOG_ERROR, "Invalid attached picture size: %d.\n", len);
00109         if (s->error_recognition & AV_EF_EXPLODE)
00110             ret = AVERROR_INVALIDDATA;
00111         goto fail;
00112     }
00113     if (!(data = av_malloc(len))) {
00114         RETURN_ERROR(AVERROR(ENOMEM));
00115     }
00116     if (avio_read(pb, data, len) != len) {
00117         av_log(s, AV_LOG_ERROR, "Error reading attached picture data.\n");
00118         if (s->error_recognition & AV_EF_EXPLODE)
00119             ret = AVERROR(EIO);
00120         goto fail;
00121     }
00122 
00123     st = avformat_new_stream(s, NULL);
00124     if (!st) {
00125         RETURN_ERROR(AVERROR(ENOMEM));
00126     }
00127 
00128     av_init_packet(&st->attached_pic);
00129     st->attached_pic.data         = data;
00130     st->attached_pic.size         = len;
00131     st->attached_pic.destruct     = av_destruct_packet;
00132     st->attached_pic.stream_index = st->index;
00133     st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
00134 
00135     st->disposition      |= AV_DISPOSITION_ATTACHED_PIC;
00136     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00137     st->codec->codec_id   = id;
00138     st->codec->width      = width;
00139     st->codec->height     = height;
00140     av_dict_set(&st->metadata, "comment", ff_id3v2_picture_types[type], 0);
00141     if (desc)
00142         av_dict_set(&st->metadata, "title",   desc, AV_DICT_DONT_STRDUP_VAL);
00143 
00144     av_freep(&pb);
00145 
00146     return 0;
00147 
00148 fail:
00149     av_freep(&desc);
00150     av_freep(&data);
00151     av_freep(&pb);
00152     return ret;
00153 
00154 }
00155 
00156 static int flac_read_header(AVFormatContext *s)
00157 {
00158     int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
00159     uint8_t header[4];
00160     uint8_t *buffer=NULL;
00161     AVStream *st = avformat_new_stream(s, NULL);
00162     if (!st)
00163         return AVERROR(ENOMEM);
00164     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00165     st->codec->codec_id = AV_CODEC_ID_FLAC;
00166     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
00167     /* the parameters will be extracted from the compressed bitstream */
00168 
00169     /* if fLaC marker is not found, assume there is no header */
00170     if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
00171         avio_seek(s->pb, -4, SEEK_CUR);
00172         return 0;
00173     }
00174 
00175     /* process metadata blocks */
00176     while (!url_feof(s->pb) && !metadata_last) {
00177         avio_read(s->pb, header, 4);
00178         avpriv_flac_parse_block_header(header, &metadata_last, &metadata_type,
00179                                    &metadata_size);
00180         switch (metadata_type) {
00181         /* allocate and read metadata block for supported types */
00182         case FLAC_METADATA_TYPE_STREAMINFO:
00183         case FLAC_METADATA_TYPE_CUESHEET:
00184         case FLAC_METADATA_TYPE_PICTURE:
00185         case FLAC_METADATA_TYPE_VORBIS_COMMENT:
00186             buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00187             if (!buffer) {
00188                 return AVERROR(ENOMEM);
00189             }
00190             if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
00191                 RETURN_ERROR(AVERROR(EIO));
00192             }
00193             break;
00194         /* skip metadata block for unsupported types */
00195         default:
00196             ret = avio_skip(s->pb, metadata_size);
00197             if (ret < 0)
00198                 return ret;
00199         }
00200 
00201         if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
00202             FLACStreaminfo si;
00203             /* STREAMINFO can only occur once */
00204             if (found_streaminfo) {
00205                 RETURN_ERROR(AVERROR_INVALIDDATA);
00206             }
00207             if (metadata_size != FLAC_STREAMINFO_SIZE) {
00208                 RETURN_ERROR(AVERROR_INVALIDDATA);
00209             }
00210             found_streaminfo = 1;
00211             st->codec->extradata      = buffer;
00212             st->codec->extradata_size = metadata_size;
00213             buffer = NULL;
00214 
00215             /* get codec params from STREAMINFO header */
00216             avpriv_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);
00217 
00218             /* set time base and duration */
00219             if (si.samplerate > 0) {
00220                 avpriv_set_pts_info(st, 64, 1, si.samplerate);
00221                 if (si.samples > 0)
00222                     st->duration = si.samples;
00223             }
00224         } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
00225             uint8_t isrc[13];
00226             uint64_t start;
00227             const uint8_t *offset;
00228             int i, chapters, track, ti;
00229             if (metadata_size < 431)
00230                 RETURN_ERROR(AVERROR_INVALIDDATA);
00231             offset = buffer + 395;
00232             chapters = bytestream_get_byte(&offset) - 1;
00233             if (chapters <= 0)
00234                 RETURN_ERROR(AVERROR_INVALIDDATA);
00235             for (i = 0; i < chapters; i++) {
00236                 if (offset + 36 - buffer > metadata_size)
00237                     RETURN_ERROR(AVERROR_INVALIDDATA);
00238                 start = bytestream_get_be64(&offset);
00239                 track = bytestream_get_byte(&offset);
00240                 bytestream_get_buffer(&offset, isrc, 12);
00241                 isrc[12] = 0;
00242                 offset += 14;
00243                 ti = bytestream_get_byte(&offset);
00244                 if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA);
00245                 offset += ti * 12;
00246                 avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
00247             }
00248             av_freep(&buffer);
00249         } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) {
00250             ret = parse_picture(s, buffer, metadata_size);
00251             av_freep(&buffer);
00252             if (ret < 0) {
00253                 av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n");
00254                 return ret;
00255             }
00256         } else {
00257             /* STREAMINFO must be the first block */
00258             if (!found_streaminfo) {
00259                 RETURN_ERROR(AVERROR_INVALIDDATA);
00260             }
00261             /* process supported blocks other than STREAMINFO */
00262             if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
00263                 if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) {
00264                     av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
00265                 }
00266             }
00267             av_freep(&buffer);
00268         }
00269     }
00270 
00271     return 0;
00272 
00273 fail:
00274     av_free(buffer);
00275     return ret;
00276 }
00277 
00278 static int flac_probe(AVProbeData *p)
00279 {
00280     uint8_t *bufptr = p->buf;
00281     uint8_t *end    = p->buf + p->buf_size;
00282 
00283     if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0;
00284     else                                            return AVPROBE_SCORE_MAX/2;
00285 }
00286 
00287 AVInputFormat ff_flac_demuxer = {
00288     .name           = "flac",
00289     .long_name      = NULL_IF_CONFIG_SMALL("raw FLAC"),
00290     .read_probe     = flac_probe,
00291     .read_header    = flac_read_header,
00292     .read_packet    = ff_raw_read_partial_packet,
00293     .flags          = AVFMT_GENERIC_INDEX,
00294     .extensions     = "flac",
00295     .raw_codec_id   = AV_CODEC_ID_FLAC,
00296 };