diff options
| -rw-r--r-- | libavformat/segafilmenc.c | 116 |
1 files changed, 56 insertions, 60 deletions
diff --git a/libavformat/segafilmenc.c b/libavformat/segafilmenc.c index 11ed279a05..42249d4eff 100644 --- a/libavformat/segafilmenc.c +++ b/libavformat/segafilmenc.c @@ -29,7 +29,9 @@ * http://wiki.multimedia.cx/index.php?title=Sega_FILM */ +#include "libavutil/avassert.h" #include "libavutil/intreadwrite.h" +#include "libavcodec/bytestream.h" #include "avformat.h" #include "internal.h" #include "avio_internal.h" @@ -160,11 +162,13 @@ static int film_init(AVFormatContext *format_context) } if ((ret = avio_open_dyn_buf(&film->header)) < 0) return ret; + ffio_fill(film->header, 0, 16 + 32 + 16); return 0; } -static int shift_data(AVFormatContext *format_context, int64_t shift_size) +static int write_header(AVFormatContext *format_context, uint8_t *header, + unsigned header_size) { int ret = 0; int64_t pos, pos_end; @@ -173,11 +177,12 @@ static int shift_data(AVFormatContext *format_context, int64_t shift_size) int read_size[2]; AVIOContext *read_pb; - buf = av_malloc(shift_size * 2); + buf = av_malloc(header_size); if (!buf) return AVERROR(ENOMEM); read_buf[0] = buf; - read_buf[1] = buf + shift_size; + read_buf[1] = header; + read_size[1] = header_size; /* Write the header at the beginning of the file, shifting all content as necessary; * based on the approach used by MOV faststart. */ @@ -190,25 +195,20 @@ static int shift_data(AVFormatContext *format_context, int64_t shift_size) return ret; } - /* mark the end of the shift to up to the last data we wrote, and get ready - * for writing */ - pos_end = avio_tell(format_context->pb); - avio_seek(format_context->pb, shift_size, SEEK_SET); + /* Mark the end of the shift to up to the last data we are going to write, + * and get ready for writing */ + pos_end = avio_tell(format_context->pb) + header_size; + pos = avio_seek(format_context->pb, 0, SEEK_SET); /* start reading at where the new header will be placed */ avio_seek(read_pb, 0, SEEK_SET); - pos = avio_tell(read_pb); -#define READ_BLOCK do { \ - read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], shift_size); \ - read_buf_id ^= 1; \ -} while (0) - - /* shift data by chunk of at most shift_size */ - READ_BLOCK; + /* shift data by chunk of at most header_size */ do { int n; - READ_BLOCK; + read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], + header_size); + read_buf_id ^= 1; n = read_size[read_buf_id]; if (n <= 0) break; @@ -224,81 +224,75 @@ static int shift_data(AVFormatContext *format_context, int64_t shift_size) static int film_write_header(AVFormatContext *format_context) { int ret = 0; - unsigned sample_table_size, stabsize, headersize, packet_count; - AVIOContext *pb = format_context->pb; + unsigned stabsize, headersize, packet_count; FILMOutputContext *film = format_context->priv_data; AVStream *video = NULL; - uint8_t *sample_table; + uint8_t *header, *ptr; /* Calculate how much we need to reserve for the header; * this is the amount the rest of the data will be shifted up by. */ - sample_table_size = avio_get_dyn_buf(film->header, &sample_table); - packet_count = sample_table_size / 16; - sample_table_size = packet_count * 16; - stabsize = 16 + sample_table_size; + headersize = avio_get_dyn_buf(film->header, &header); + if (headersize < 64) { + av_assert1(film->header->error < 0); + return film->header->error; + } + packet_count = (headersize - 64) / 16; + stabsize = 16 + 16 * packet_count; headersize = 16 + /* FILM header base */ 32 + /* FDSC chunk */ stabsize; - ret = shift_data(format_context, headersize); - if (ret < 0) - return ret; - /* Seek back to the beginning to start writing the header now */ - avio_seek(pb, 0, SEEK_SET); - - /* First, write the FILM header; this is very simple */ - - ffio_wfourcc(pb, "FILM"); - avio_wb32(pb, 48 + stabsize); + /* Write the header at the position in the buffer reserved for it. + * First, write the FILM header; this is very simple */ + ptr = header; + bytestream_put_be32(&ptr, MKBETAG('F', 'I', 'L', 'M')); + bytestream_put_be32(&ptr, headersize); /* This seems to be okay to hardcode, since this muxer targets 1.09 features; * videos produced by this muxer are readable by 1.08 and lower players. */ - ffio_wfourcc(pb, "1.09"); - /* I have no idea what this field does, might be reserved */ - avio_wb32(pb, 0); + bytestream_put_be32(&ptr, MKBETAG('1', '.', '0', '9')); + /* I have no idea what the next four bytes do, might be reserved */ + ptr += 4; /* Next write the FDSC (file description) chunk */ - ffio_wfourcc(pb, "FDSC"); - avio_wb32(pb, 0x20); /* Size of FDSC chunk */ + bytestream_put_be32(&ptr, MKBETAG('F', 'D', 'S', 'C')); + bytestream_put_be32(&ptr, 0x20); /* Size of FDSC chunk */ video = format_context->streams[film->video_index]; /* The only two supported codecs; raw video is rare */ switch (video->codecpar->codec_id) { case AV_CODEC_ID_CINEPAK: - ffio_wfourcc(pb, "cvid"); + bytestream_put_be32(&ptr, MKBETAG('c', 'v', 'i', 'd')); break; case AV_CODEC_ID_RAWVIDEO: - ffio_wfourcc(pb, "raw "); + bytestream_put_be32(&ptr, MKBETAG('r', 'a', 'w', ' ')); break; } - avio_wb32(pb, video->codecpar->height); - avio_wb32(pb, video->codecpar->width); - avio_w8(pb, 24); /* Bits per pixel - observed to always be 24 */ + bytestream_put_be32(&ptr, video->codecpar->height); + bytestream_put_be32(&ptr, video->codecpar->width); + bytestream_put_byte(&ptr, 24); /* Bits per pixel - observed to always be 24 */ if (film->audio_index > -1) { AVStream *audio = format_context->streams[film->audio_index]; int audio_codec = get_audio_codec_id(audio->codecpar->codec_id); - avio_w8(pb, audio->codecpar->channels); /* Audio channels */ - avio_w8(pb, audio->codecpar->bits_per_coded_sample); /* Audio bit depth */ - avio_w8(pb, audio_codec); /* Compression - 0 is PCM, 2 is ADX */ - avio_wb16(pb, audio->codecpar->sample_rate); /* Audio sampling rate */ + bytestream_put_byte(&ptr, audio->codecpar->channels); /* Audio channels */ + bytestream_put_byte(&ptr, audio->codecpar->bits_per_coded_sample); /* Audio bit depth */ + bytestream_put_byte(&ptr, audio_codec); /* Compression - 0 is PCM, 2 is ADX */ + bytestream_put_be16(&ptr, audio->codecpar->sample_rate); /* Audio sampling rate */ } else { - /* Set all these fields to 0 if there's no audio */ - avio_w8(pb, 0); - avio_w8(pb, 0); - avio_w8(pb, 0); - avio_wb16(pb, 0); + /* If there is no audio, all the audio fields should be set to zero. + * ffio_fill() already did this for us. */ + ptr += 1 + 1 + 1 + 2; } /* I have no idea what this pair of fields does either, might be reserved */ - avio_wb32(pb, 0); - avio_wb16(pb, 0); + ptr += 4 + 2; /* Finally, write the STAB (sample table) chunk */ - ffio_wfourcc(pb, "STAB"); - avio_wb32(pb, stabsize); + bytestream_put_be32(&ptr, MKBETAG('S', 'T', 'A', 'B')); + bytestream_put_be32(&ptr, stabsize); /* Framerate base frequency. Here we're assuming that the frame rate is even. * In real world Sega FILM files, there are usually a couple of approaches: * a) framerate base frequency is the same as the framerate, and ticks @@ -308,12 +302,14 @@ static int film_write_header(AVFormatContext *format_context) * The latter occurs even in cases where the frame rate is even; for example, in * Lunar: Silver Star Story, the base frequency is 600 and each frame, the ticks * are incremented by 25 for an evenly spaced framerate of 24fps. */ - avio_wb32(pb, av_q2d(av_inv_q(video->time_base))); + bytestream_put_be32(&ptr, av_q2d(av_inv_q(video->time_base))); - avio_wb32(pb, packet_count); + bytestream_put_be32(&ptr, packet_count); - /* Finally, write out each packet's data to the header */ - avio_write(pb, sample_table, sample_table_size); + /* Finally, shift the data and write out the header. */ + ret = write_header(format_context, header, headersize); + if (ret < 0) + return ret; return 0; } |