[Ffmpeg-devel] [PATCH] flv with streamed ByteIO support

[Michael Niedermayer]

Hi

On Thu, Sep 21, 2006 at 07:34:17PM +0900, nazo wrote:
> Streamed ByteIO like http can't use url_fskip and url_fseek. So the 
> attached patch is implemented url_fskip for streams and changed 
> url_fseek to url_fskip. I tested in youtube.

[...]
> -        if (av_rescale_q(st->codec_info_duration, st->time_base, AV_TIME_BASE_Q) >= MAX_STREAM_DURATION) {
> +        if (av_rescale_q(st->codec_info_duration, st->time_base, AV_TIME_BASE_Q) >= MAX_STREAM_DURATION
> +            || ((&ic->pb)->is_streamed && i==ic->nb_streams)) {

i see no sense in this change


[...]
> -    url_fseek(&s->pb, offset, SEEK_SET);
> +    url_fskip(&s->pb, offset - url_ftell(&s->pb));

rejected this is the same, or at least should be, if not thats a bug


[...]
> -    next= size + url_ftell(&s->pb);
> +    next = size + url_ftell(&s->pb);

cosmetic


[...]
>  {
> -    AVStream *st = s->streams[stream_index];
> -    int index = av_index_search_timestamp(st, timestamp, flags);
> +    AVStream *st;
> +    int index;
> +    if(url_is_streamed(s))
> +        return -1;
> +    st = s->streams[stream_index];
> +    index = av_index_search_timestamp(st, timestamp, flags);

rejected this function must not be called if the if() is true


[...]
> +static void fill_buffer(ByteIOContext *s)
> +{
> +    int len;
> +
> +    /* no need to do anything if EOF already reached */
> +    if (s->eof_reached)
> +        return;
> +
> +    if(s->update_checksum){
> +        if(s->buf_end > s->checksum_ptr)
> +            s->checksum= s->update_checksum(s->checksum, s->checksum_ptr, s->buf_end - s->checksum_ptr);
> +        s->checksum_ptr= s->buffer;
> +    }
> +
> +    len = s->read_packet(s->opaque, s->buffer, s->buffer_size);
> +    if (len <= 0) {
> +        /* do not modify buffer if EOF reached so that a seek back can
> +           be done without rereading data */
> +        s->eof_reached = 1;
> +    if(len<0)
> +        s->error= len;
> +    } else {
> +        s->pos += len;
> +        s->buf_ptr = s->buffer;
> +        s->buf_end = s->buffer + len;
> +    }
> +}
> +

moving a function around is a purely cosmetical change which is not allowed
unless its 1. needed (its not here) and 2. its a seperate patch


>  static void flush_buffer(ByteIOContext *s)
>  {
>      if (s->buf_ptr > s->buffer) {
> @@ -161,6 +189,14 @@
>  
>  void url_fskip(ByteIOContext *s, offset_t offset)
>  {
> +    if(url_is_streamed(s)){
> +        while(s->buf_end - s->buf_ptr < offset){
> +            offset -= s->buf_end - s->buf_ptr;
> +            fill_buffer(s);
> +        }
> +        s->buf_ptr += offset;
> +        return;
> +    }
>      url_fseek(s, offset, SEEK_CUR);

url_fskip() behavior MUST NOT differ from url_fseek(SEEK_CUR)

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is